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Table of contentsMaterials screws & nuts Arrangement / Design / Assembly Definition of terms used in screwed fastening technology 2 Selection of fasteners – Estimation of screw diameters 29 Fatigue resistance – Strength und dynamic load 30 Screws (Property class 3.6 to 12.9) – Mechanical and physical properties – Minimum ultimate tensile loads – Material, heat treatment, chemical composition – Characteristics at elevated temperatures Nuts (Property class 04 to 12) – Mechanical properties – Minimum bolt stress for nuts ≥0,5 d and <0,8 d – Test loads – Chemical compositions Set screws (Property class 14 H to 45 H) – Mechanical properties – Materiela, heat treatment, chemical composition Screws, bolts, nuts – Marking – Pairing screws and nuts 4 5 6 6 7 7 8 9 10 10 11 12 Screws and nuts for high an low temperatures – Mechanical properties, min. 0,2% yield strength – Typical values for thickness and static modulus of elasticity – Typical values for the coefficient of thermal expansion, thermal conductivity and heat capacity – Table of materials for temperatures from –200 °C and over +300 °C – Pairing materials – Ductility, Yield strength and tensile strength of steels at low temperatures – Elastic elongation 16 Stainless steel fasteners – Designation of property classes – Chemical composition – Distinctive properties A1 / A2 / A3 / A4 / A5 – Mechanical properties – Minimum breaking torque – Elongation limits at elevated temperatures – Marking of screws and nuts – Chemical stability, Technical arguments 17 17 18 19 19 20 20 21 Fasteners of various materials – Non-ferrous materials – Special materials – Thermoplastics 22 23 24 13 13 13 14 14 15 Corrosion protection – Galvanic process – Reduction of the risk of hydrogen embrittlement – Coating thickness for parts with external thread – Further galvanic coating processes – Further surface treatments 26 26 27 28 28 Length of engaged thread – Recommended min. lengths of engaged thread in cut internal threads on components Surface pressure mounted – Limiting surface pressures for different materials – Hex cap screws – Cheese head screw with hex socket – Surface pressure under the scrw head 31 32 33 33 34 Friction and friction coefficients – Relation of friction coefficient classes to guideline values for various surfaces 35 Tightening method, tightening factor αA 36 Prestressing forces and tightening torques – Working with the guideline values – Metric coarse thread – Metric fine thread, Polyamide 6.6 – Double-end studs with reduced shank – Screws made from austenitic stainless steel A1 / A2 / A4 – Fasteners with ehxagon and hexalobular socket and flat heads – Locking scrwes and nuts, flange screws and nuts – High-strength structural steel bolts (HV-sets) 37 38 39 39 40 40 41 42 Securely fastened connections 43 – Summary of constructive measures – List of additional ways of securing screwed connnections 44 Shear loads for pins – Dowel pins (clamping sleeves) heavy finish 45 Construction recommendations – Direct screwed connections in metals – Direct assembly in thermoplastics – Sheet metal joints – Selection criteria for self-tapping Ensat® inserts – Internal drives for screws 46 48 52 54 56 Metric ISO threads – Basic concept, Clearance fit, Tolerance fields – Limits and selection series for coarse threads – Limits and selection series for fine threads – Permissible tolerances for plastic fasteners 58 59 60 60 Tolerances / Tables / Standards – Basic tolerances and tolerances fields – SI units system / Conversion tables – Conversion tables: metric-USA / USA-metric – Hardness comparison table – Designations of different national standards 61 62 64 65 66 www.bossard.com © 2005 by Bossard Terminology Rm = max. tensile force F Stress area As N mm2 (Stress area As [mm2] of thread, see T.033) Tensile strength at rupture in cylindrical shank: F Tensile test on machined screw Rm = max. tensile force F cylindrical starting cross-section N mm2 max. tensile force Tensile test on full size screw yeld point Yield strength Rel [N/mm2] The yield strength is the tensile stress from which elongation begins to increase disproportionately with increasing tensileforce. A plastic elongation remains after relief. Tensile strength at rupture in thread: tensile force Tensile strength Rm [N/mm2] The minimum tensile strength of a screw is the tensile stress from which there could be a rupture in the shank or the thread (not in the head/shank joint). If full size screws are tested, the yield strength can only be approximately established. Under ISO 898 Part 1, the exact yield strength and elongation after fracture can only be determined using machined samples. Exceptions are stainless steel screws A1–A4 (ISO 3506). max. tensile force limit Rp0,2 0,2% limit Rp0,2 [N/mm2] The yield strength of harder material is difficult to determine. The 0,2 limit is defined as the tensile stress from which aplastic elongation of exactly 0,2% remains after relief. In practice, screws may be stressed by tightening and underworking load no more than up to the yield strength or the 0,2 limit. tensile force elongation elongation Elongation at fracture A [%] This occurs on loading up to the rupture point of the screw. In a defined shank area, the remaining plastic elongation isdetermined using machined screws. Exceptions: screws A1–A4, where this is measured on fullsize screws (ISO 3506). do measuring length Lo = 5 x do www.bossard.com T.00 © 2005 by Bossard Home Terminology Wedge tensile strength The tensile strength on whole screws is established and the head strength simultaneously tested on an angular load. The rupture must not occur in the head/shank joint. F Head soudness The head of the screw must with stand several hammer blows. After being bent to a specified angle, the shank head fillet shall not show any signs of cracking. For details see ISO 898, part 1. Hardness Generally speaking hardness is the resistance which the material offers to the penetration of a test body under adefined load (see ISO 898, Part 1). Hardness comparison tables, see T.065. Vickers hardness HV: ISO 6507 Pyramid (encompasses the complete hardness range usual for screws). Impact strength (Joule) ISO 83 is the impact work used in the notched bar impact bending test. A notched sample is taken from near the surface of the screw. This sample is broken with a single blow in apendulum ram impact testing machine, yielding information on the microstructure, melting behaviour, inclusion content, etc.. The measured value cannot be included in design calculations. Surface defects are slag inclusions, material overlaps and grooves stemming from the raw material. Cracks, on the other hand, are crystalline ruptures without inclusions. For details, see DIN 267 Part 20, ISO 6157. Decarburization of the surface is generally a reduction in the carbon content of the surface of the thread of heat treated screws, see ISO 898 Part 1. Brinell hardness HB: ISO 6506 Ball. Rockwell hardness HRC: ISO 6508 Cone. www.bossard.com T.00 © 2005 by Bossard Home 1) 2) www.005. min.2 5. % min. 238 HB or 99.6 to 12.015 — Reduction of hardness 20 HV max.2 apply tomachined test specimens. Percent elongation after fracture A in % Reduction area after fracture Z 5.00 © 2005 by Bossard Home .91 — — 640 660 0.5 — — — 32 34 3.11 5.5 d and other products which cannot be tensile-tested (e.8 Stress at 0.3.3 5.2.5 Rockwell hardness HR 5.Screws Property class 3. the tensile loads.12 Breaking torque. For the property classes 4.15 Head soudness Minimum height of non-decarburized thread zone.18 8) Maximum depth of complete decarburization. 5) Vickers hardness HV F ≥ 98 N Brinell hardness HB F = 30 D2 5. 3) For structural bolting the limit is 12 mm.3 5. nominal value min. 9) The yield stress ratio according to the designation of the property class and the minimum stress at 0. there is an increased risk of nut stripping in the case of inadvertent over-tightening inducing a load in excess of proofing load. min. HRC max. J min. it is permissible to measure the stress at 0. 8) In cases where the lower yield stress ReL cannot be determined. Sp / ReL or Sp / Rp0. In accordance with ISO 6157-1 or ISO 6157-3 as appropriate For bolts of porperty class 8. screws and studs according to ISO 898. 6) A hardness reading taken at the end of bolts.16 5. 5.6 4. max.9 — — 900 940 0.94 400 400 420 120 130 2206) 114 124 2096) 67 71 — — 956) — — 240 320 300 240 340 300 — — 0. 4) Minimum tensile properties apply to products of nominal length I ≥ 2.10 5. HRB HRC HRB max. any increase in hardness at the surface which indicates that the surface hardness exceeds 390 HV is not acceptable.88 380 440 580 970 — — 12 600 650 830 see ISO 898-7 12 10 9 — 52 48 The values for full size bolts and screws (not studs) shall not be smaller than the minimum values for tensile strength shown in 5. KU in J 5.93 180 225 25 22 90 52 — 180 190 4.8 in diameters d ≤ 16 mm. Applies only to nominal thread diameters d ≤ 16 mm.91 — — 720 720 0. max.2 — 25 — 30 30 25 8 48 44 20 15 no fracture — mm — /2 H1 2 1 /3 H1 /4 H1 3 0.91 0.88 — — 1080 1100 0.9 900 900 290 360 276 342 — 28 — 37 1000 1040 320 380 304 361 — 32 — 39 1200 1220 385 435 366 414 — 39 — 44 7) 400 420 0. E 5.13 Strength under wedge loading5) 5. 7) Surface hardness shall not be more than 30 Vickers points above the measured core hardness on the product when readings of both surface and core carried out at HV 0. nominal value min.6 Surface hardness HV 0. they are not test values.8 5.8 and 6.4 Mechanical and physical property Tensile strength Rm in N/mm2 4).82) 10.9 Stress under proofing load Sp 5. For property class 10.94 0. MB Nm min.g.92 — — 640 640 0.8 the values for Rel are given for calculation purposes only.6 310 280 — — 20 9.6 300 330 95 0. 5) When testing full-size bolts.8 8.7 lower yield stress Rel in N/mm 5.2 N/mm2 min.9 Mechanical and physical properties of bolts.bossard.9.81) d≤ d> 16mm3) 16mm3) 500 600 800 800 500 520 600 800 830 155 160 190 250 255 250 320 335 147 152 181 238 242 238 304 318 79 82 89 — — — — — 22 23 99. These values if received from tests of full size bolts and screws will vary because of processing method and size effects.1 und 5.29) in N/mm2 5. due to head configuration). G Hardness after retempering Surface integrity 2 nominal value min.5 d.2 % non-proportional elongation Rp0.com T. part 1 The mechanical properties are given for tests at room temperature.2% non-proportional elongation Rp0. screws and studs shall be 250 HV. screws and studs. Subclause number 5. Property class 5. Minimum hardness applies to products of length l < 2.8.2 % non-proportional elongation Rp0.5 HRB maximum. which are to be applied for the calculation of Rm shall meet the values given on page T.9 480 480 — — 0.9 12.8 6. Reference to ISO 898–2 is recommended. min.17 5.14 Impact strength. 8 8.8 6.5 M16 x 1. For structural bolting the values are 70 000. part 1 Minimum ulitmate tensile loads3) – ISO metric coarse (standard) pitch thread Thread1) M 3 M 3. Entsprechen nicht den Prüfkräften nach ISO 898 part 1 1) 2) 3) Minimum ultimate tensile loads3) – ISO metric (fine) threads ISO 898 / 1 Thread M 8x1 M10 x 1 M10 x 1.2 20.9 36.9 Minimum ultimate tensile load (As · Rm) in N 1 660 2 240 2 900 4 690 6 630 9 540 12 100 19 100 27 800 38 000 51 800 63 400 80 800 100 000 116 000 152 000 185 000 229 000 270 000 322 000 2 010 2 710 3 510 5 680 8 040 11 600 14 600 23 200 33 700 46 000 62 800 76 800 98 000 121 000 141 000 184 000 224 000 278 000 327 000 390 000 2 110 2 850 3 690 5 960 8 440 12 100 15 400 24 400 35 400 48 300 65 900 80 600 103 000 127 000 148 000 193 000 236 000 292 000 343 000 410 000 2 510 3 390 4 390 7 100 10 000 14 400 18 300 29 000 42 200 57 500 78 500 96 000 122 000 152 000 176 000 230 000 280 000 347 000 408 000 488 000 2 620 3 530 4 570 7 380 10 400 15 000 19 000 30 200 43 800 59 800 81 600 99 800 127 000 158 000 184 000 239 000 292 000 361 000 425 000 508 000 3 020 4 070 5 270 8 520 12 100 17 300 22 000 34 800 50 600 69 000 94 000 115 000 147 000 182 000 212 000 275 000 337 000 416 000 490 000 586 000 4 020 5 420 7 020 11 350 16 100 23 100 29 200 46 400 67 4002) 92 0002) 125 0002) 159 000 203 000 252 000 293 000 381 000 466 000 576 000 678 000 810 000 4 530 5 230 6 140 6 100 7 050 8 270 7 900 9 130 10 700 12 800 14 800 17 300 18 100 20 900 24 500 26 000 30 100 35 300 32 900 38 100 44 600 52 200 60 300 70 800 75 900 87 700 103 000 104 000 120 000 140 000 141 000 163 000 192 000 — 200 000 234 000 — 255 000 299 000 — 315 000 370 000 — 367 000 431 000 — 477 000 560 000 — 583 000 684 000 — 722 000 847 000 — 850 000 997 000 — 1 020 000 1 200 000 Where no thread pitch is indicated in a thread designation.8 8.00 © 2005 by Bossard Home .com T.6 4.Screws Property classes 3.5 M24 x 2 M27 x 2 M30 x 2 M33 x 2 M36 x 3 M39 x 3 Nominal stress area AS mm2 39.0 84. respectively.9 Minimum ultimate tensile load (AS · Rm) in N 12 900 21 300 20 200 30 400 29 100 41 200 55 100 71 300 89 000 110 000 127 000 164 000 205 000 251 000 285 000 340 000 15 700 25 800 24 500 36 800 35 200 50 000 66 800 86 400 109 000 133 000 154 000 198 000 248 000 304 000 346 000 412 000 16 500 27 100 25 700 38 700 37 000 52 500 70 100 90 700 114 000 140 000 161 000 208 000 261 000 320 000 363 000 433 000 19 600 32 300 30 600 46 100 44 100 62 500 83 500 108 000 136 000 166 000 192 000 248 000 310 000 380 000 432 000 515 000 20 400 33 500 31 800 47 900 45 800 65 000 86 800 112 000 141 000 173 000 200 000 258 000 323 000 396 000 450 000 536 000 23 500 38 700 36 700 55 300 52 900 75 000 100 000 130 000 163 000 200 000 230 000 298 000 373 000 457 000 519 000 618 000 31 360 51 600 49 000 73 700 70 500 100 000 134 000 179 000 226 000 276 000 319 000 412 000 515 000 362 000 718 000 855 000 35 300 40 800 47 800 58 100 67 100 78 700 55 100 63 600 74 700 82 900 95 800 112 400 79 300 91 600 107 500 112 000 130 000 152 000 150 000 174 000 204 000 — 225 000 264 000 — 283 000 332 000 — 346 000 406 000 — 399 000 469 000 — 516 000 605 000 — 646 000 758 000 — 791 000 928 000 — 900 000 1 055 000 — 1 070 000 1 260 000 www.8 9. (see ISO 261 and ISO 262).9 12.78 8.8 9.1 88.6 Property class 5.bossard.6 4.8 10.5 M 4 M 5 M 6 M 7 M 8 M10 M12 M14 M16 M18 M20 M22 M24 M27 M30 M33 M36 M39 Nominal stress area As mm2 5. 95 500 and 130 000 N.6 to 12.2 92.78 14. coarse pitch is specified.1 28.5 M18 x 1.8 5.03 6.6 Property class 5.1 125 167 216 272 333 384 496 621 761 865 1030 3.2 64.5 M20 x 1.3 115 157 192 245 303 353 459 561 694 817 976 3.25 M12 x 1.8 6.9 Minimum ultimate tensile loads according to ISO 898.8 10.5 M14 x 1.5 M22 x 1.6 4.9 12.8 5.5 61.25 M12 x 1.6 58.6 4. 035 0. Where elements are specified in combinations of two.6 8.154) 0. quenched and tempered7) — 0.55 0.003 Tempering temperature °C min. For products made from these steels.83) 9.62) 4. heat treatment.55 0.30%.g.95).28 0.20 P max.00 © 2005 by Bossard Home .003 425 0. Boron. quenched and tempered Carbon steel.05 0.9 may be necessary in order to achievesufficient hardenability.005 % provided that non-effective boron is controlled by addition of titanium and/or aluminium.003 380 Boron content can reach 0.55 0. A metallographically detectable white phosphorous enriched layer is not permitted for property class 12. part 1 Continuous operating at elevated service temperature may result in significant stress relaxation.20%.06 0. 10.035 0.035 0.25% (ladle analysis). quenched and tempered or Carbon steel with additives (e. parte 5 3.035 0.82) 6.035 0.9 leads to a different response to stress relaxation at higher temperatures.035 0. nickel 0. 0.05 0. vanadium 0. quenched and tempered Carbon steel with additives (e.003 — 0. quenched and tempered Carbon steel with additives (e. — max.035 0.25 0.96) 12. Characteristics at elevated temperatures according to ISO 898.7% for 9. Boron.55 0.035 0.9 All the properties set out in the table on page T.g.bossard.9 on surfaces subjected to tensile stress.20 0. lead 0.035 0. Boron.9 Temperature + 20 °C + 100 °C + 200 °C + 250 °C + 300 °C Lower yield stress.50 0.Screws Property class 3.05 0.55 0.9.55 0. Free cutting steel is allowed for these property classes with the following maximum sulfur. Typically 100 h service at 300 °C will result in a permanent reduction in excess of 25 % of the initial clamping load in the bolt due to decrease in yield stress. quenched and tempered7) Alloyed steel. three or four elements concerned.35 0.55 0. the minimum manganese content shall be 0. it is intended that there should be a sufficient hardenabiltity to ensure a structure consisting of approximately 90% martensite in the core of the threaded sections for the fasteners in the «as-hardened» condition before tempering. the identification sign indicating the strength class must also be underlined.2% non-proportional elongation [N/mm2] 300 270 230 215 195 640 590 540 510 480 940 875 790 745 705 940 — — — — 1100 1020 925 875 825 www. 0.06 0.30%.25 0.11%. the limit value to be applied for class determination is 70% of the sum of the individual limit values shown above for the two. phosphorus and lead contents: sulfur 0. Mn oder Cr).003 — 0.82) 8.9 12.9 10.13 0. However the lower tempering temperature for 10.035 0. This alloy steel shall contain at least one of the following elements in the minimum quantity given: chromium 0.6 to 12.8 10. 0.8 and 0. For nominal diameters above 20 mm the steels specified for property class 10.96).9 Materials.6 5.035 0. Boron.55 0.34%.154) 0.154) 0. molybdenum 0.35 0.003 425 0.004 for 10.8 10.62) 5.06 — 0. The chemical composition and tempering temperature are under investigation. Mn or Cr). In case of plain carbon boron alloyed steel with a carbon content below 0.40 0.06 B max.35%.035 0.8 and 10. phosphorus 0.9 must be achieved.62) 4.003 425 0.035 1) 0. 8).6% for property class 8. quenched and tempered or Carbon steel.035 0. 9) 2) 3) 4) 1) 5) 6) 7) 8) 9) min. chemical compositions according to ISO 898.204) 0.035 0. Mn or Cr).035 0.25 0. 0.com T. Mn or Cr).05 S max.g. Property class 5. three or four and have alloy contents less than those given above. 6) 10. For the materials of these property classes. quenched and tempered or Carbon steel. quenched and tempered or Alloyed steel. — 0. ReL or stress at 0.035 0.035 0.10%.g.003 340 Chemical composition limits (check analysis) % Property class Material and heat treatment C Carbon steel Carbon steel with additives (e. part 2 The standard values for strip resistance relate to the given bolt classes.5 d < 0. Property class of nut 04 05 Proof load stress of the nut N/mm2 380 500 Minimum stress in the core of bolt when stripping occurs for bolts with porperty class N/mm2 6.Nuts Property classes 04 to 12 Mechanical properties of nuts with coarse (standard) threads according to ISO 898. part 2 Thread-Ø Proof stress 04 Vickers hardness Proof stress 05 Vickers hardness HV over — M 4 M 7 M10 M16 to M 4 M 7 M10 M16 M39 Thread-Ø Sp N/mm2 HV min. max. N/mm2 min.bossard. 1150 1040 1140 1040 1140 1150 2951) 5351) 3532) 2722) 1040 1140 1160 272 353 1050 1170 1190 1060 — — — 1200 Nuts style 1 (ISO 4032) Nuts style 2 (ISO 4033) 1) 2) Remarks The minimum hardness values are binding only for nuts for which a test stress measurement cannot be performed and for hardened and tempered nuts.8 260 290 8.9 330 410 12. while the thread of the nut will strip if it is paired with screws of higher property classes. max. max.8 300 370 10. N/mm2 min. 302 353 Sp N/mm2 900 915 940 950 920 min. 180 200 233 HV max. max. Minimum bolt stress when stripping occurs for nuts with nominal height ≥ 0. 272 353 500 8 Vickers hardness Proof stress 9 Vickers hardness HV over — M 4 M 7 M10 M16 to M 4 M 7 M10 M16 M39 Sp N/mm2 800 855 870 880 920 min. 302 Property class 4 5 6 Proof Vickers hardness Proof Vickers hardness Proof Vickers hardness stress stress stress HV HV HV Sp Sp Sp N/mm2 min. N/mm2 min. 520 600 — — — 580 670 590 680 130 150 610 700 302 302 510 117 302 630 146 720 170 Property class 10 12 Proof Vickers hardness Proof Vickers hardness Proof Vickers hardness stress stress stress HV HV HV Sp Sp Sp N/mm2 min. 188 302 Sp N/mm2 380 Proof stress min. max.8 d according to ISO 898.com T. max. 170 188 max. The minimum values are guide values for all other nuts. max. The exterior thread may be expected to strip if the nuts are paired with screws of lover property classes. max. N/mm2 min.9 350 480 www.00 © 2005 by Bossard Home . 8 d according to DIN 267. The buyer and the manufacturer must agree minimum hardnesses for these particular nuts.6 58.03 6.0 84.bossard.78 14. If the designation of the thread does not indicate thread pitch then the reference is to coarse threads (see DIN 13).5 M 4 M 5 M 6 M 7 M 8 M10 M12 M14 M16 M18 M20 M22 M24 M27 M30 M33 M36 M39 Stressed cross-section of the test mandrel As mm2 5. part 4 Nuts with test loads above 350000 N (values below the stage lines shown) can be excluded from a test load trial.1 28.com T. 1) Thread1) M 3 M 3. 1) Test loads for nuts 0.3 115 157 192 245 303 353 459 561 694 817 976 4 5 Property class (code number) 6 8 10 12 Test load (As x Sp).5 M 4 M 5 M 6 M 7 M 8 M10 M12 M14 M16 M18 M20 M22 M24 M27 M30 M33 M36 M39 Stressed cross-section of the test mandrel As mm2 5.3 115 157 192 245 303 353 459 561 694 817 976 04 05 4 5 6 Property class 8 9 10 12 Test load (As x Sp).03 6.2 20.78 8.1 28. N — 1910 2580 3340 5400 7640 11000 13 900 22000 32000 43700 59700 73000 93100 115100 134100 174400 213200 263700 310500 370900 — 2500 3400 4400 7100 10000 14500 18300 29000 42200 57500 78500 96000 122500 151500 176500 229500 280500 347000 408500 488000 Typ 1 — — — — — — — — — — — 97900 125000 154500 180000 234100 286100 353900 416700 497800 Typ 1 2600 3550 4550 8250 11700 16800 21600 34200 51400 70200 95800 121000 154000 190900 222400 289200 353400 437200 514700 614900 Typ 1 3000 4050 5250 9500 13500 19400 24900 39400 59000 80500 109900 138200 176400 218200 254200 330500 403900 499700 588200 702700 Typ 1 4000 5400 7000 12140 17200 24700 31800 50500 74200 101200 138200 176600 225400 278800 324800 422300 516100 638500 751600 897900 Typ 2 — — — — — — — — — — — 170900 218100 269700 314200 408500 499300 617700 727100 868600 Typ 2 4500 6100 7900 13000 18400 26400 34400 54500 80100 109300 149200 176600 225400 278800 324800 422300 516100 638500 751600 897900 Typ 2 5200 7050 9150 14800 20900 30100 38100 60300 88500 120800 164900 203500 259700 321200 374200 486500 594700 735600 866000 1035000 Typ 2 5700 7700 10000 16200 22900 32900 41700 66100 98600 134600 183700 — — — — — — — — — Typ 2 5800 7800 10100 16300 23100 33200 42500 67300 100300 136900 186800 230400 294000 363600 423600 550800 673200 832800 980400 1171000 If the description of the thread does not include thread pitch then the reference is to coarse threads (see ISO 261 and ISO 262).6 58.00 © 2005 by Bossard Home .78 14.78 8.9 36.2 20. part 2 Thread1) M 3 M 3. N — — — — — — — — — — — 76800 98000 121000 141000 184000 224000 277000 327000 390000 2500 3400 4400 7100 10000 14500 18300 29000 42100 57500 78500 96000 122000 151000 176000 230000 280000 347000 408000 488000 3000 4050 5250 8500 12000 17300 22000 35000 50500 69000 94000 115000 147000 182000 212000 276000 336000 416000 490000 585000 4000 5400 7000 11400 16000 23000 29000 46000 67000 92000 126000 154000 196000 242000 282000 367000 448000 555000 653000 780000 5000 6800 8750 14200 20000 29000 36500 58000 84000 115000 157000 192000 245000 303000 353000 459000 561000 694000 817000 976000 6000 8150 10500 17000 24000 34700 43000 69500 10000 138000 188000 230000 294000 364000 423000 550000 673000 833000 980000 1170000 www.Nuts Property classes 04 to 12 Test loads for nuts according to ISO 898.9 36.0 84. part 2 Property class 4 .058 0.34% phosphorus 0. phosphorus and lead are permitted: sulfur 0.150 0. 10 and 12 must be quenched and tempered. 9 102) 122) 1) 1) 1) — 041) 052) — C max. unless other arrangements have been agreed upon between the buyer and the supplier.35% 1) For these strength classes it may be necessary to add alloys in order to achieve the mechanical properties of the nuts. — 0.com T.45 0.50 0.058 Nuts of these strength classes may be made from automatic steel. max. 0.150 0.048 S max.6 8. www. 8 (style 1 above M16).060 0.30 0.58 0.58 Chemical composition in terms of % by weight (check analysis) Mn P min.11% lead 0.060 0.25 0.58 0.bossard. 0.048 0.Nuts Property classes 04 to 12 Chemical compositions of nuts according to ISO 898.00 © 2005 by Bossard Home . 2) Nuts of property classes 05. When using automatic steel the following maximum proportions of sulphur.5 . nickel. 22 H und 33 H nicht für Gewindestifte mit Innensechskant Vickers hardness HV 45 H 450 560 428 532 – – 45 53 580 For further details of the mechanical properties of set screws please refer to ISO 898 part 5. – – 33 HRC max. part 5 Property class Material 14 H High-carbon steel 1).19 0.35% is permitted. — 0. 276 285 418 min.6 to 39 mm.bossard. 3) Steel with Pb max. phosphorus and sulphur can be used: Pb = 0.3 max.34%. max. Case hardening is permitted for square headed grub screws.50 — 0. 2) Heat treatement Chemical composition in % by weight (random analysis) C P S max. 133 209 314 Brinell hardness HB. which are not subject to tension and which have threads of diameter from 1.05 45 H Alloy steel 3). 105 – – Rockwell hardness min. F = 30 D2 max. 1) 2) Other steels may also be used for strength class 45H. Property class1) Mechanical properties 14 H 22 H 33 H min.05 0. heat treatment and chemical composition according to ISO 898. min. = 0.11 0. part 5 The mechanical properties apply to grub screws and similar. Materials. – 30 44 Surface hardness HV 0. 4) The alloyed steel must contain one or more alloy element: chrome.15 22 H High-carbon steel 3) quenched and tempered 0.05 0.Set screws Property classes 14 H to 45 H Mechanical properties according to ISO 898.05 Automatic steel with ghe following maximum content of lead.50 — 0.35%. P = 0.05 33 H High-carbon steel 3) quenched and tempered 0. molybdenum.11%. 290 300 440 min. www. 4) quenched and tempered 0.05 0. max. if the grub screws satisfy the requirements of the tightening test in ISO 898 part 5. made from unalloyed or alloyed steel. – 320 450 1) Festigkeitsklasse 14 H.010 © 2005 by Bossard Home .50 0.com T. 140 220 330 max. S = 0. vanadium or boron. 75 95 – HRB max.50 — 0. 9 (see table on page T. For adjustment bolts with locking. part 1 Property class 5.8 8. The´hexagon nuts must be marked with an indentation on the bearing surface or on the side or by embossing on the chamfer. the symbol 10.6 to 12.9 12.6 4. Marking of studs according to ISO 898.011 © 2005 by Bossard Home . part 2 Identification with the manufacturer is mark and property class is mandatory for hexagon nuts with thread diameter d ≥ 5 mm.6 5.8 12. Embossed markings must not protrude beyond the bearing surface of the nut. where the shape of the screw always allows (it – preferably on the head).8 9.8 XYZ Marking is obligatory for property classes of or higher than 8.9 8.9 Examples of marking on socket head cap screws and hexalobular head bolts and screws.9 Marking symbol 8.8 and is preferably to be made on the threaded part by an indentation.92) 12.6 4.6 8. Marking of nuts according to ISO 898.8 9.8 ABCD 8.com T.8 9.006). the marking must be on the side of the nut.9 and sockethead cap screws 8.8 The symbols shown in the table on the right are also autorised as a method of identification.8 10.8 6.9 with thread diameter d ≥ 5 mm.6 4.9 shall be underlined: 10.6 5. When low carbon martensitic steels are used for property class 10.8 5. Marking is required for bolts of nominal diameter of or greater than 5 mm.8 to 12.9 Marking 3.8 10.9 1) 2) Identification with the manufacturer’s mark and the property class is mandatory for hexagon screws 3.Screws Bolts Nuts Marking of screws according to ISO 898.8 Examples of marking on hexagon screws ABCD XYZ 12.bossard.8 6.8 8.9 1) The full-stop in the marking symbol may be omitted.9 12. part 1 Property class 3.6 4. 8. ABCD AB CD 8.8 5.8 10. AB AB 8 AB 8 Example of marking with the property class designation AB Example of marking with the code symbol (clock-face system) www. 8 d according to ISO 898.8 8.9 12.8 10.6 5. part 4 Characteristic 4 5 6 8 10 12 Indentification mark |4| |5| |6| |8| |10| |12| Property class Hexagon nuts with nominal thread diameter d ≥ 5 mm must be marked with the property class on the bearing surface or on the side. This is advisable for a bolt / nut assembly stressed higher than the yield stress or the stress under proof load.com T. to DIN 934 and DIN 935 made from free-cutting steel.Screws Bolts Nuts Marking of nuts according DIN 267. |8| |8| For hexagon nuts with nominal thread diameter d ≥ 5 mm acc.012 © 2005 by Bossard Home . www.6 4. part 2 Assignment of possible property classes of screws and nuts 4 5 6 8 9 10 12 Nuts Mating bolts Property class of nut Property class 3. Groove Pairing scrwes and nuts ≥ 0. Embossed markings must not protrude beyond the bearing surface of the nut. nuts of a higher property class are preferable to nuts of a lower property class. the marking must also include a groove on one chamfer of the nut (up to property class 6).8 5.9 Typ 1 Diameter range > M16 ≤ M16 ≤ M39 ≤ M39 ≤ M39 ≤ M16 ≤ M39 ≤ M39 Typ 2 Diameter range > M16 — ≤ M39 — ≤ M39 ≤ M39 — ≤ M39 ≤ M16 — > M16 ≤ M39 ≤ M16 — ≤ M39 Remark: In general.6 4.6 4.8 6.bossard.6 4.8 3.8 9. 9 13.9 14.1181 1.a.85 211 204 196 186 177 164 127 7.5 17.7711 1.com T.4923 X5CrNi18-10 X5CrNiMo17-12-2 X5NiCrTi26-15 1. 0.4980 d [Kg/dm3] 20 100 200 hardened and tempered steels 300 400 500 600 7.1 12.013 © 2005 by Bossard Home . thermal conductivity and heat capacity excerpt from DIN EN 10269 (old DIN 17240) Coefficient of thermal expansion in 10—6 / K between 20 °C and Material abbreviation Name Material number C35E 40CrMoV4-7 1. 15 500 18.a.a.1 17. [N/mm2] [%] [J] hardened and tempered steels 500 to 650 22 55 500 to 650 22 55 860 to 1060 14 50 850 to 1000 14 30 800 to 950 14 27 900 to 1050 12 20 work-hardened austenitic steels 700 to 850 20 80 700 to 850 20 80 900 to 1150 15 50 20 100 200 300 400 500 300 300 730 700 600 750 270 270 702 670 560 701 229 229 640 631 530 651 192 192 562 593 480 627 173 173 475 554 420 577 375 470 335 495 350 350 600 155 175 580 127 145 560 110 127 540 98 115 520 92 110 490 600 293 305 430 Typical values for thickness and static modulus of elasticity according to DIN EN 10269 (old DIN 17240) Material abbreviation Name Static modulus of elasticity E in kN/mm2 at a temperature [ °C] of Density Material number C35E 40CrMoV4-7 X19CrMoNbVN11-1 X22 CrMoV12-1 1.7 12.5 17.4980 d ≤ 35 d ≤ 35 d ≤ 160 Name Tensile strenght Elongation at facture notch bar impact value Minimum value for the 0. n.Screws and nuts Mechanical properties min.bossard.7711 1.0 n.4301 1.a.2 at N/mm2 at a temperature [° C] of Rm Amin.2 n.0 17.5 18.7 216 209 200 190 179 167 127 work-hardened austenitic steels 7.9 8.0 17.4980 100 °C 200 °C 300 °C 400 °C 500 °C hardened and tempered steels 11.4401 1.4301 1.0 8.2% yield strength values at increased temperatures for high and low temperatures according to DIN EN 10269 (old DIN 17240) Diameter range Material abbreviation Material number d [mm] C35E 35B2 42CrMo4 40CrMoV4-7 X22CrMoV12-1 X19CrMoNbVN11-1 1. KVmin.0 200 194 186 179 172 165 — 2111) 2061) 2001) 1921) 1831) 1731) 1621) Dynamic modulus of elasticity 1) Typical values for the coefficient of thermal expansion.1 16.0 18.1181 1.4401 1.7225 1.5 600 °C Thermal conductivity at 20 °C W m·K Specific thermal conductivity at 20 °C J kg · K 42 33 460 13.4401 1.5511 1.4301 1.4913 1.1181 1. n.4923 1.2% limit Rp0.0 16.4913 d ≤ 60 d ≤ 60 d ≤ 60 d ≤ 100 d ≤ 160 d ≤ 160 X5CrNi18-10 X5CrNiMo17-12-2 X5NiCrTi26-5 1. work-hardened austenitic steels www.7711 X5CrNi18-10 X5CrNiMo17-12-2 X5NiCrTi26-15 1. VH VW S SD SB +350 °C +350 °C +350 °C +400 °C +540 °C +500 °C +580 °C +580 °C +650 °C +650 °C +700 °C Material number Marking Utilisation temperatur limits 26 CrMo4 12 Ni 19 X 5 CrNi 18 10 X 5 CrNi 18 12 X 6 CrNiTi 18 10 1. As a result of the molybdenum content when below the temperature shown these can no longer be expected to have a homogenous austenitic micro-structure. part 13 Material abbreviation Material number Marking Utilisation temperatur limits 1.7711 1.5511 1.com T.4301 1.7219 1.014 © 2005 by Bossard Home .4923 1.4303 1. 35 B 2 Ck35.015 T.0501 1. part 13 Material abbreviation 1) 2) 1) 2) – 60 °C –120 °C –200 °C –200 °C –200 °C – 60 °C –200 °C – 60 °C –200 °C Screws with head.7258 1.4541 KA KB A2 A2 A2 X 5 CrNiMo 17 12 2 1.1181 1. high-temperature resistant and sub-zero resistant steels according to DIN 267. 24 CrMo 5 24 CrMo 5 21 CrMoV 5 7 21 CrMoV 5 7 X 22 CrMoV 12 1 40 CrMoV 4 7 X 22 CrMoV 12 1 X 19 CrMoVNbN 11 1 X 8 CrNiMoBNb 16 16 X 5 NiCrTi 26 15 NiCr 20 TiAl X 8 CrNiMoBNb 16 16 X 5 NiCrTi 26 15 Ni Cr 20 TiAl www. Screw without head. part 13 Material Screw Nut Ck 35 35 B 2 24 CrMo 5 21 CrMoV 5 7 C 35 N.7709 1. 1) 2) For strength values see pictures on page T.Screws and nuts for high and low temperatures Table of materials for temperature over +300 °C according to DIN 267.4571 A4 C 35 N oder C 35 V Ck 35 35 B 2 24 CrMo 5 21 CrMoV 5 7 40 CrMoV 4 7 X 22 CrMoV 12 1 X 19 CrMoVNbN 11 1 X 8 CrNiMoBNb 16 16 X 5 NiCrTi 26 15 NiCr20 TiAl Table of materials for low temperatures from ­­–200 °C to –10 °C according to DIN 267.4986 1.4952 Y YK YB G GA GB V.5680 1.015 Pairing materials for screws and nuts from heat-resistant. 35 B 2. Ck 35.4913 1.4401 A4 X 6 CrNiMo Ti 17 12 2 1. C 35 V.bossard.4980 2. com T.bossard.Ductility of steels at low temperatures according to manufacurer’s specifications Screws an nuts for high and low temperatures 70 26 CrMo 4 X 12 CRNi 18 9 60 12 Ni 19 X 12 CrNi 18 9 X 10 CrNiTi 18 10 X 10 CrMoTo 18 10 50 40 [%] Necking at rupture K Elongation at rupture A Impact strength specimen DVM 30 12 Ni 19 26 CrMo4 20 X 12 CrNi 18 9 X 10 CrNiTi 18 10 12 Ni 19 26 CrMo4 10 0 -200 -150 -100 -50 DVM [J] 200 100 0 0 +20 Temperature [˚C] Yield strength and tensile strength of steels at low temperatures according to manufacurer’s specifications [N/mm2] 1300 1200 1100 1000 900 800 700 26 CrMo 4 12 Ni 19 600 CrNi 18 9 { XX 12 10 CrNiTi 18 10 26 CrMo 4 (bis -120˚) { 12 Ni 19 500 400 300 X 12 CrNi 18 9 X 10 CrNiTi 18 10 200 100 Tensile strength Rm Yield strength Rel or Rp 0.015 © 2005 by Bossard Home .2 0 -200 -150 -100 -50 0 +20 Temperature [˚C] www. 519 0.278 0.481 0.304 0.307 0.291 0.195 0.427 0.607 0.683 0.19 0.161 0.354 0.448 0.438 211 211 E [103 N/mm2] GA GB V VW Overview of material T.473 0.116 0.214 0.016 © 2005 by Bossard Home .673 0.251 0.209 0.328 0.242 0.bossard.278 0.213 0.33 0.309 0.252 0.734 0.34 0.485 0.376 0.202 0.325 0.483 0.43 0.412 0.418 0.164 0.com T.708 0.394 0.149 0.155 0.27 0.182 0.065 0.286 0.109 0.394 0.197 0.51 0.291 0.139 0.194 0.2 www.143 0.205 0.161 0.407 0.582 196 216 216 Example X 8 CrNiMoBNb 16 16 = [S] = 500 N/mm2 Rp 0.405 0.175 0.504 0.455 0.146 0.626 0.136 0.466 0.446 0.2 length of reduced shank L = 220 mm Elastic elongation l = 0.358 0.543 0.056 0.371 0.557 0.437 0.228 0.252 0.213 0.633 0.563 0.215 0.4 0.102 0.563 0.272 0.349 0.175 0.364 0.531 0.2 0.441 0.51 0.423 0. column S for L = 0.218 0.186 0.204 0.162 0.322 0.102 0.155 0.167 0.382 0.140 0.255 0.696 0.504 0. 70% of yield stress at room temperature 0.487 0.546 0.291 0.107 0.506 0.524 0.427 0.407 0.329 0.251 0.232 0.365 0.31 0.321 0.557 0.277 0.152 0.177 0.537 0.455 0.116 0.33 0.28 0.273 0.253 0.112 0.084 0.088 0.175 0.394 mm = 220 mm where: 0.43 0.658 0.543 0.336 0.466 0.349 0.237 0.074 0.524 0.528 0.194 0.093 0.248 0.485 0.158 0.121 0.233 0.582 0.409 0.388 0.369 0.534 0.304 0.759 211 211 Calculation l = A FV FV L Length of reduced shank FV · L [mm] E·A l [mm] = elastic elongation under preload FV FV [N] = preload E [N/mm2] = elasticity module = cross section area of A [mm2] reduced shank L [mm] = reduced shank length 216 S SB 0.233 0.394 0.388 0.279 0.136 0.464 0.603 0.125 0.255 0.491 0.302 0.292 0.146 0.7 FV A = 70% de Rp 0.65 0.179 0.501 0.272 0.291 0.234 0.263 0.38 0.582 0.348 0.446 0.186 0.69 0.465 0.Screws and nuts for high and low temperatures Elastic elongation of bolts with reduced shanks according to DIN 2510 Materials YK G L = [mm] 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 250 260 270 280 290 300 0.58 0.177 0.127 0.233 0.014 Elastic elongation ­l in [mm] prestressed up to approx.13 0.223 0.131 0.269 0.31 0.233 0.35 0.117 0.346 0.26 0.419 0.7 · 500 220 196000 see table. 03 16–18.050 0.0 2.0 0. nuts style 1 50 70 80 Jam nuts 025 035 040 025 soft workhardened heavily workhardened 70 110 50 055 soft hardened and tempered 50 70 80 45 035 040 020 030 soft hardened hardened and and tempered tempered soft 60 workhardened Descriptions using a letter/figure combination mean the following: Abbreviation of composition group: A = austenitic chromium-nickel steel A2 – 70 Abbreviation of chemical composition: 1 = free-cutting steel with sulphur additive 2 = cold-heading steel alloyed with chromium and nickel 3 = cold-heading steel alloyed with chromium and nickel stabilised with Ti. 700 N/mm2) 80 = 1/10 of tensile strength (min.03 19–19 — 9–12 1 1.12 0. tantalum 1) www.0 0.5 2–3 10.com T.0 0. unless otherwise indicated.03 16–18. Ta 4 = cold-heading steel alloyed with chromium. Ta Abbreviation of property class: 50 = 1/10 of tensile strength (min.08 Chemical composition in % (maximum values. They are characterised by impressive corrosion resistance and excellent mechanical properties.045 0.15–0. 250 N/mm2 035 = proof stress min.08 0.0 2.200 0.017 © 2005 by Bossard Home .35 16–19 0. Nb.5–14 1 stabilised against intergranular corrosion through addition of titanium. Austenitic stainless steels are divided into 5 main groups whose chemical compositions are as follows: Steel group A1 A2 A31) A4 A51) C 0. 350 N/mm2 040 = proof stress min.08 0. 500 N/mm2) 70 = 1/10 of tensile strength (min. nickel and molybdenum 5 = cold-heading steel alloyed with chromium.5 0.0 0. possibly niobium.75–2.7 5–10 1.045 0.0 2.25 1. Nb.bossard. rest iron (Fe)) Si Mn P S Cr Mo Ni Cu 1.Stainless steel fasteners Designation of property classes according to ISO 3506 Austenitic Compositions groups Identification of steel grades A1 Martensitic A2 A31) A4 A51) C1 C4 Ferritic C3 Fi Property classes Screws. 800 N/mm2) Flat nuts: 025 = proof stress min.045 0.10 0. nickel and molybdenum stabilised with Ti.0 2.03 15–20 — 8–19 4 1.5 2–3 10–15 1 1. 400 N/mm2 Chemical composition of austenitic stainless steels according to ISO 3506 More than 97% of all fasteners made from stainless steels are produced from this steel composition group.0 6. 030 11.55 0.5 N max.5 0.5 0.5 0.4305 Properties for machining – rust-resistant to a certain degree – acid-resistant to a certain degree – weldable to a certain degree A2 A3 1.045 0. 0.5 to 14.2 to 2. Martensitic steels 0. 0.0 to 13.15 / Cu 1.50 to 3.15 V 0.4539 1.Stainless steel fasteners Chemical composition of rust-resisiting stainless steel Material number C Si max.5 0.04 0.0 1.5 8.0 1.15 to 0.5 6.50 0.0 1. 0.0 to 23.04 0.4580 Highest resistance to corrosion – rust-resistant – highly acid-resistant – easily weldable A3. 0.04 1.010 19.0 to 19.4435 1.4571 1. 1.5 0.4310 1.045 0.4303 1.5 2.25 / Cu 0.07 max.4439 1.4116 1.0 1.030 0.0 to 9.04 0.5 10.05 to 0. 0.00 0.50 max.08 to 0.0 2. 0.0 8.00 to 5.7 1.030 16.22 Al 0.04 0.0 0.00 0.4006 1.20 to 0. 0.00 / N max.10 to 0.8 10.80 0.4305 1.4541 1.0 0.70 Distinctive properties A1 / A2 / A3 / A4 / A5 Material designation Material number A1 1.045 0.50 to 0.80 0.5 4. Further details on the chemical stability of rust-resistant and acid-resistant steels can be found on page T.70 to 1.0 to 13.03 max.4301 1.0 0.0 to 10.80 0.0 2.0 to 21.030 12.0 to 18.4306 1.4550 Standard quality – rust-resistant – acid-resistant – weldable to a certain degree A4 A5 1.045 Chemical composition.0 0.08 1.10 to 0.5 0.0 2.0 to 26.5 to 13.0 to 19.7 1.50 to 3. 0.00 to 2.20 max.4568 1.11 N max. Mn max.0 1.02 max. 0.4105 1.4462 1.0 max.0 1. 1.50 Ni Other max. 0.4401 1.0 1.22 N 0.0 0. 0.5 to 18. 0. % by mass S Cr Mo max. annealing or when used at high temperatures.035 0.030 14.0 2.4401 1.5 to 17.03 max.015 16. 1. 0.0 2.040 0.60 0.35 17.0 1.5 N max.08 0. 0.30 Austenitic steels 0.0 6.0 2.0 to 15.04 0.0 1.75 V max.0 1.0 to 19.0 1.5 to 14.33 to 0.50 to 0.4436 1.5 2.15 max.bossard.0 1.0 1.0 1.4122 0.4590 1.4571 max.0 N 0.0 2.10 0. P max. 0.045 0.50 0.60 0.0 to 18.45 1.45 to 0.045 0. 0.12 to 0.5 1.43 to 0.030 0.0 4.00 to 2.0 2.com T.00 to 5.11 N max.0 to 15.4110 1.00 to 7.0 1.0 2.030 15.015 16.80 to 1.0 24.09 max.4435 1.0 to 26.0 to 21.5 to 1.0 2.5 to 15.11 N 0.50 Ti 5xC ≤ 0.0 0.5 24.0 to 19. 0. A5: as A2.5 to 6.018 © 2005 by Bossard Home .4439 1.00 0.5 to 18. A4 but stabilised against intergranular corrosion follwong welding.5 to 18.0 0.5 to 7.0 2.0 4.0 12.0 2.15 0.5 1.11 Cu max.0 12. 0.0 to 10.021 www.02 max.035 16.030 16.4529 1.4034 1.010 19.015 21.025 16.030 17.045 0.030 17.07 max. 0.015 13.0 6.0 0.4301 1.03 max.4300 1.15 to 0.00 0.48 to 0. 21) N/mm2 min.5 d ≤ m < 0. A2 A3. A4–70 (tensile strength of 700 N/mm2). Minimum breaking torque MBmin.8 d 0.3 23 46 80 210 Minimum breaking torque MB.1 2.8 4.8 d 50 70 80 Screws Stress at 0.6 3. Nuts thin nuts style 1 m ≥ 0.019 © 2005 by Bossard Home . for screws made from austenitic steel with threads M1.5 9.5 M 3 M 4 M 5 M 6 M 8 M10 M12 M16 50 0.com T.96 1.6 1.. the range of diameters M5–M24 and for lengths up to 8x thread-ø (8xd).3 8.5 d ≤ m < 0.24 0.8 7. A5 m = nut height d = nominal thread diameter The standard commercial quality covers strength classes A2–70.48 0.9 1.Stainless steel fasteners Mechanical properties for fasteners made from austenitic stainless steel according to ISO 3506 Steel group Steel grade Property class of screw Thread diameter range Tensile strength Rm N/mm2 min.15 0. 0.8 13 32 65 110 290 80 0.2% permanent strain Rp 0. 1) 2) Use of screws of strength class 80 is only economically justifiable if the components are made from stainless steel (high strength). 500 700 800 1) Austenitic Steel group Austenitic A1. Nm Property class 70 0. We keep a wide range available for you from stock.4 0.8 d 500 250 700 350 800 400 All values are calculated values and refer to the stressed cross-section of the thread.8 15 37 74 130 330 www. A4 A5 Steel grade A1 A2. 50 70 80 ≤ M 39 ≤ M 243) ≤ M 243) Thread diameter range Property class of nuts Nuts style 1 m ≥ 0. The elongation under fracture is to be determined for the whole screw and not for unscrewed test pieces.6 M 2 M 2.3 0.7 5.bossard.6 d 0. 210 450 600 thin nuts 0. 3) Strength requirements for diameters above M24 must be specially agreed on between the buyer and the manufacturer.4 d 0. min.6 to M16 (normal thread) according to ISO 3506 Threads M 1. A3 A4.3 d Nuts Stress under proof load SP N/mm2 min.2 0.8 d 025 035 040 d mm ≤ 39 ≤ 243) ≤ 243) Elongation after fracture A2) mm min. the property class and the manufacturer’s mark. A4 +100 °C +200 °C +300 °C +400 °C 85% 80% 75% applies for property classes 70 and 80 70% Marking of screws and nuts according to ISO 3506 Requirement Screws and nuts made from stainless austenitic steels mustbe marked. Nuts A2-70 XYZ A2-70 A4 Alternative groove marking XYZ A2-50 Ø>s XYZ A2-50 A2 A4 Caution! Only those fasteners marked to standard will have the desired properties. www.2 at elevated temperatures as % of the values at room temperature according to ISO 3506 Stainless steel fasteners For applicability at low temperature see page T.com T.2 in % Steel grade A2.014. The marking must show the steel group. ReL and Rp0. Studs Nuts Nuts from minimal diameter M5 must be marked with the steel group.020 © 2005 by Bossard Home . Locking screws must be marked on the shaft or screw end. A2-70 Property class Steel group Socket head cap screws XYZ XYZ A2-70 Studs Bolts from nominal diameter M6 must be marked on theshank or the end of the thread with the steel group. the property class and the manufacturer‘s mark. Products not marked to standard will often only correspond to property classes A2–50 or A4–50. Hexagon screws manufacturer’s mark XYZ Screws Hexagon and hexagon socket screws from nominal diameter M5 must be marked.bossard.Elongation limit Rp 0. the property class and the manufacturer’s mark. good appereance Rusty screws create a bad impression. Lick-resistant Small children must not be able to get within reach of and lick small. Easy to clean and hygienic Products or efflorescences caused by corrosion can build up on bright-polished or zinc-coated fasteners which then become difficult to remove. No risk to health Cutting yourself on a rusty part can lead to blood poisoning. ISO standard 3506 defines rust and acid-resistant steels. 1. This often results in damage to the parts. A2. then even these steels will corrode! General A2 above water. and so always remain workable. Its resistance to corrosion is lower than that of A2. pockets of water. The corrosion resistance drops dramatically. the parts jam up when being assembled. If access to atmospheric oxygen is blocked by an unfavourable style of construction or through dirt. and can lead to a sudden failure of the steel part. Please avoid: Cracks. 1.com T. Martinistic chrome steels (e. This is often very difficult to see from the outside. The customer loses trust in the product. This will reduce their load-bearing capacity. rules: inland climate A4 under water.4112) are normally used for rust-resistant retaining rings and washers. separation joints. The corrosion resistance of these steels is lower than that of austenitic chrome-nickel steels. In order to disassemble the unit the fasteners have to be destroyed. Advantages Avoidance of potential problems Bright-finished surface. Austenitic chrome-nickel steel is Magnetic fasteners used in the construction of types of apparatus or measuring devices can lead to almost entirely non-magnetic disruptions. If this is damaged it uses atmospheric oxygen to regenerate itself. A4. Savety Corrosion reduces the strength and operational reliability of the fasteners. 1. Recent experience indicates that there is a risk of stress corrosion cracking.Stainless steel fasteners Chemical stability based on information provieded by the to manufacturer’s Austenitic steels A1. which gives it a good machinability.021 © 2005 by Bossard Home . No traces of rust Red rust can discolour white-coloured plastic components and textiles and make them unusable. They become weak points. It also contains details of their mechanical properties. poor ventilation. A2 and A4 obtain their resistance to corrosion through a surface protective layer of oxide. The reference data with respect to corrosion resistance Indications on resistance to corrosion are preferably obtained from laboratory and practical trials! Ask for information on our «BossAnalysis» service. zinc-coated or cadmium-coated parts. or chemical blackening or a roughening of the surface.g. In order to reduce this risk the depth of the nuts can be selected so that the fitted rings are not subjected to stress.bossard.4116. Food grade material Parts made from zinc-coated steel must not be allowed to come into contact with foodstuffs. layers of dirt The resistance to corrosion can be reduced in the presence of a coating (prevents access to the air). chemical composition and a number of notes on the selection of the right steel for high and low temperature applications. This gives rise to additional problems of corrosion. Magnetic parts attract iron filings. Good temperature resistance At temperatures above 80 °C the chromating on zinc-plated and chrome-plated fasteners is destroyed. No problems during maintenance work Rusty screws or nuts just cannot be unscrewed. Technical arguments for the use of fasteners made from rust-resistant austenitic chrome-nickel steels A1. The screw and nuts are bright-polished If the permissible thickness of the coating on galvanically finished screws is exceeded. and this involves considerable force and effort. Media containing chlorine can under certain conditions lead to dangerous inter-crystalline corrosion. coastal climate A1 this steel contains small particles of sul- phur. www.4110. 0 · 10—6 F20 kaltv.5 0.4 1.9 2 2.022 © 2005 by Bossard Home .0 · 10—6 F54 soft Rp 0. good electrical conductivity Designation of the material CU4 CU5 AL1 AL2 AL3 Minimum breaking torque1) [Nm] 0.5 0.4365 AL 6 hardened T6 (F 42) hardened T73 (F 50) hardened T73 (F 51) < M30 440 510 6 Al Cu4 Mg Si very good level of corrosionresistance low strength very good level of corrosionresistance medium strength still a good level of corrosionresistance high strength high strength mountings but lowest level of corrosion resistance *) high strength mountings but lowest level of corrosion resistance *) subject to stress corrosion cracking due to the high copper content Properties of screws an nuts made from copper alloys selection based on information provided by the manufacturer’s Material designation Material number 2.16 0.3555 AL 2 soft < M14 work hardened M14 / M20 205 200 310 280 6 6 Al Si1 Mg Mn 6082 3.1 0.08 0.8 1.15 0.2315 AL 3 hardened T6 < M6 M6 / M20 260 250 320 310 7 10 Al Mg1 Si 0. State of Density Electrical thermal expansion r from structure conducitivity mm EN Rm kg m mm · k F= W · mm2 a 30/100 °C 28839 10 dm3 F20 soft 58.25 0.0 Cu 1 8.5 2. modulus of elasticity = 70000 N/mm2 Material designation EN AW- Material number EN AW- Old DIN designation Stage of preparation of the Material from EN screws / nuts number 28839 Used for Rp 0.9 3.1 5. 56.8 1.3 1.45 0. E-Modul N/mm2 % N/mm2 200 / 270 40 110 000 >350 7 >290 45 110 000 >370 27 330 / 440 40 125 000 540 / 640 8 CuNi12 Zn24 (nickel silver) 2.1 0.10 0.3 1.2 N/mm2 <150 <320 <250 >250 <290 mechanical properties at 20 °C Rm AS min.9 4 0.124 · 75 hardened 8.27 0.12 0.6 M2 M2.8 3.3 1.5 M4 M5 0.23 0.5 Mg Cu 7075 3.3 ~10 16.8 0.5 0.7 0.1 2.6 1.0321 · 26 2.0730 · 10 Coefficient of Des.13 0.28 0.12 0.6 0.14 0.67 4.0040 2.06 0.8 1.7 2.7 1 2.4 0.21 0.1 0.4 4.4 2.2 1.07 0.06 0.0 16.10 0.1325 AL 4 < M20 290 420 6 Al Zn6 Cu Mg Zr 7050 3.0 F29 soft Cu 2 8.4 18.8 1.1 1.9 0.8 kg/dm3.2 4.11 0.0 · 10—6 >540 >780 >540 >830 12 10 CuBe2 2.47 0.8 > 18. coefficient of thermal expansion = 23.43 0.6 0.0853 · 73 Cu 5 2.2 N/mm2 Rm N/mm2 AS % Al Mg5 5019 3.0730 · 30 CuNi1.5 20.9 3.7 0.7 · 10—6 1050/ 1400 1200/ 1500 2 — Minimum breaking torque for screws up to M5 according to ISO 8839 the torque test is to be carried out in according to ISO 898-1 1) >440 Threads nominal Ø CU1 CU2 CU3 M1.2 0.2 · 10—6 F37 kaltv.22 0.6 · 10–6 · K–1.4144 — < M30 400 500 6 Al Zn5. 125 000 corrosion resistant.24 0.44 15.8 0.3 0.21 0.3 1.94 17.8 Cu Mn 6013 — — hardened T8 < M20 370 400 10 2017 A 3.bossard.0065 E-Cu 58 OF-Cu CuZn 37 (brass) 2.9 1.45 0.8 AL4 AL5 AL6 0.0321 · 10 2.3 0.11 0.8 Used for parts with a high electrical conductivity normal fastenings very good corrosion resistant silver colours high-strength 140 000 fastening.5 www. with very 144 000 good electrical conductivity high-strength fastening.0857 · 73 — hardened hardened 8.com T.5 M3 M3.5 1.9 1.5Si CuNi3Si 2.Fasteners of various materials Non-ferrous materials Properties of screws and nuts made from alluminium alloys selection based on information provided by the manufacturers The values in the table are for: density = 2.0 > 15. F34 soft — 8. com T. phosphoric acid and alkaline solutions. Excellent resistance to corrosion in oxidising metals which contain chloride. Also suitable for parts used in presses and forges. Monel® 400 K-500 2. in chemical processes and plants. Chemical industry. sulphates and sulphites. vehicle engineering etc.4634 Titanium Gr. No recommended for strongly oxidising agents. Nickel-copper alloy with high strength and toughness over a wide range of temperatures.4969 2. in the production of fibres and paper. exhaust cleaning systems. housings etc.7235 Gr.4851 2.Fasteners of various materials Special materials Designation Material number Hastelloy B B-2 2. Highly corrosion resistant nickel-molybdenum alloy with excellent resistance against reducing media. power station technology. 4 3.4816 2.4952 2.4610 C-22 2.4856 2. Application: Rotating components subject to high temperatures. 11 3. iron and copper salts (see Hastelloy C). based on information provided by the manufacturer. particularly against moist media which contain chloride. Hastelloy® G G-3 2.4951 2. combustion chamber components. pumps. Even resists corrosion from caustic materials. Application: Components subject to strong chemical action. 7 3. Application: Components for weight-saving construction requiring high strength.5 3. 3 Gr. in particular against all concentrations of hydrochloric acid up to boiling point.7164 / 3. particularly suitable for the production of phosphoric acid and nitric acid. Highly corrosion resistant nickel-chrome-molybdenum alloy with particularly high resistance against aggressive. organic acids such as vinegar and formic acid.4600 ® Description and range of application. mountings. The nickel-based chrome materials are alloys with a particularly high fatigue strength and resistance to oxidisation. mechanically stressed components exposed to seawater etc. Application: ® In chemical process engineering. A wide variety of penetration hardening methods allow the relaxation and creep behaviour to be controlled. sulphuric acid and phosphoric acid. seawater desalination. sulphuric acid.4819 C-2000 2. washers. medical technology etc.4668 Nickel-chrome alloy with good industrial properties at high temperatures up to and above 1000°C and an excellent resistance to oxidation. desulphurization plant etc.4375 Application: Application: Nimonic 75 80A 90 105 2.4603 Nickel-chrome-iron alloy with excellent resistance to corrosion in oxidising media.bossard. fasteners. Excellent resistance to corrosion by salt water and a large number of acids and alkaline solutions.7055 3.7225 Pure titanium alloyed with palladium. chromates and cyanogen compounds.7065 Heat treatment plant.4360 2.4619 G-30 2. Chemical and petrochemical plant. subject to strong oxidising stresses.4675 Components subject to strong chemical action. oxidising and reducing media – bleach solutions which contain free chorine. chlorides and chlorates. blades. Reactive material with high strength in relation to its low density. For high mechanical stresses at temperatures up to 1000 °C.023 © 2005 by Bossard Home . ventilators and fans. 1 Gr.4602 C-276 2. chemical industry etc. fasteners. waste disposal etc. chlorites. springs. Titanium Gr.7035 3. Application: Application: Components for the air and space industries. Titanium Gr. nuclear energy technology. particularly in the presence of chlorides. shafts etc.7165 Titanium alloy with a high specific strength. Valves. chemical processing technology. rotating components.7025 3. 2 Gr. Application: Hastelloy® C C-4 2. Adequate resistance to oxidising and reducing gases up to 800 °C. linings. hypochlorites. moist chlorine water gas. Inconel® 600 601 625 718 2. solutions of nitrates. gas turbines.4617 B-3 2. turbo-superchargers for jet engines etc. Increased resistance to corrosion. www. Grade 11 has increased properties of deformation. Fasteners of various materials Thermoplastics Reference values of physical characteristics according to manufacturer’s data Fracture resistance % DIN 53455 Elasticity module N/mm2 DIN 53457 Ball penetration harness, 10-sec Value N/mm2 DIN 53456 Impact strength kJ/m2 DIN 53453 Ductility kJ/m2 DIN 53453 PE-HD PE-LD PP POM PA 6 PA 66 Tensile strenght N/mm2 DIN 53455 Material abbreviation DIN 7728 Density g/cm3 DIN 53479 mechanical properties 0,94 / 0,96 0,914 / 0,928 0,90 / 0,907 1,41 / 1,42 1,13 1,14 18 / 35 8 / 23 21 / 37 62 / 70 70 / 85 77 / 84 100 / 1000 300 / 1000 20 / 800 25 / 70 200 / 300 150 / 300 700 / 1400 200 / 500 1100 / 1300 2800 / 3200 1400 2000 40 / 65 13 / 20 36 / 70 150 / 170 75 100 without fracture without fracture without fracture 100 without fracture without fracture without fracture without fracture 3 / 17 8 without fracture 15 / 20 electrical properties Dielectric loss factor d DIN 53483 50 Hz 106 Hz 50 Hz 106 Hz kV / 25 µm ASTM D 149 kV / cm DIN 53481 KA KB / KC PE-HD PE-LD PP POM PA 6 PA 66 > 1017 > 1017 > 1017 > 1015 1015 1012 1014 1014 1013 1013 1010 1010 2,35 2,29 2,27 3,7 3,8 8,0 2,34 2,28 2,25 3,7 3,4 4,0 2,4 · 10–4 1,5 · 104 < 4 · 10–4 0,005 0,01 0,14 2,0 · 10–4 0,8 · 10–4 < 5 · 10–4 0,005 0,03 0,08 > 700 > 700 800 700 350 400 — — 500 / 650 380 / 500 400 600 3c 3b 3c 3b 3b 3b > 600 > 600 > 600 > 600 > 600 > 600 thermal properties Dimensional stability °C max. permanent min. permanent VSP (Vicat 5 kg) DIN 53460 ASTM D 648 1,86 / 0,45 N/mm2 Lienear coefficient of expansion K–1 · 106 Thermal conductivitiy W/mK Specific heat kJ/kg K PE-HD PE-LD PP POM PA 6 PA 66 max. short therm Operating temperature °C Material abbreviation DIN 7728 Surface leakage current resistance DIN 53480 Surface resistance W DIN 53482 Material abbreviation DIN 7728 Dielectric strength Specific resistance W cm DIN 53482 Dielectric constant DIN 53483 90 / 120 80 / 90 140 110 / 140 140 / 180 170 / 200 70 / 80 60 / 75 100 90 / 110 80 / 100 80 / 120 – 50 – 50 0 / – 30 – 60 – 30 – 30 60 / 70 — 85 / 100 160 / 173 180 200 50 35 45 / 120 110 / 170 80 / 190 105 / 200 200 250 150 90 / 110 80 80 0,38 / 0,51 0,32 / 0,40 0,17 / 0,22 0,25 / 0,30 0,29 0,23 2,1 / 2,7 2,1 / 2,5 2,0 1,46 1,7 1,7 Abbreviation / significance PE-HD High density polyethylene PE-LD Low density polyethylene PP Polypropylene POM Polymethylene, Polyacetale PA 6 Polyamide PA 66 Polyamide www.bossard.com T.024 © 2005 by Bossard Home Fasteners of various matrials Thermoplastics Water, hot Acids, dilute Acids, strong Acids, oxidised Acid hydrofluoric Detegrents, weak Detegrents, strong Saline solutions Halogen, dry EC aliphatic EC chlorinated 1 1 1 0 3 1 1 1 0 1 3 < 0,01 1 3 0 3 1 1 1 0 1 0 < 0,01 1 1 3 0 3 1 1 1 3 1 0 0,01 to 0,03 1 1 3 0 0 0 1 1 1 0 1 1 0,22 to 0,25 1 3 0 0 0 0 1 3 1 0 1 3 1,3 to 1,9 Mineral oils Greases, oils EC chlorinated, non-saturated Turpentine 1 1 3 3 1 1 0 0 < 0,01 1 0 0 3 3 0 0 < 0,01 1 3 3 3 1 1 0 0 0,01 to 0,03 3 3 1 3 1 1 1 1 3 0,22 to 0,25 3 1 3 1 1 1 0 3 3 1,3 to 1,9 1 1 1 3 3 PE-LD 3 3 3 0 PP 1 3 3 0 1 POM 1 0 3 1 PA 6 1 1 1 1 Material abbreviation PE-HD 1 resistant 3 resistant with reservation Water absorption, % ASTM D 570 Fuels PA 6 EC aromatic POM Organic acids 1 Water absorption, % ASTM D 570 Amines PP Aldehydes 1 Ether PE-LD Cetone 1 Ether-salicylic PE-HD Alcohol Water, cold Material abbreviation Chemical resistance 0 inconstant Abbreviation / significance PE-HD High density polyethylene PE-LD Low density polyethylene PP Polypropylene POM Polymethylene, Polyacetale PA 6 Polyamide www.bossard.com T.025 © 2005 by Bossard Home Corrosion protection Galvanic process Fasteners with galvanic coatings according to ISO 4042 Galvanizing – chromatizing Galvanizing followed by chromatizing of fasteners is a procedure which has proven itself in terms of both corrosion resistance and appearance. We can offer you an extensive assortment from our range in stock. You will find our surfaceprotected parts in the catalog groups 110, indicated by the green tab. tion and prevents tarnishing and discoloration of the zinc coating. The protective effect of the layer of chromate differs with the different types of procedure (see the table!). for the corrosion protection of fasteners. The new surface treatments based on chromium (VI) – free systems usually require a more complex process control and where necessary additional cover layers, since the «self-healing effect» is missing. Long-term experience gained under working conditions is largely not available and such experience is also influenced by specific conditions such as handling, transport and feeder devices. Consequently it is recommended that a review be made through the adjustment for the different operating conditions met in practice. Chromatizing (passivation) takes place immediately after the galvanizing, and is made by briefly dipping the part in solutions of chromic acid. The chromatization process increases the corrosion protec- New developments in processes involving chromium (VI)-free coatings offering the same or similar protective effect spurred onwards by environmental regulations due to EU Directives 2000/53/ EC (ELV) und 2002/95/EC (RoHS). Until now normal practice has been to use galvanic zinc coatings (ISO 4042) with chromatization based on chromium (VI) Types of procedure used for the chromatization of galvanic zinc coatings Protective effect of zinc coatings with chromatization under conditions of salt spray fog testing to DIN 50021 SS. Types of process Designation of the chromatization Chromate coating own colour transparent Colorless chromatizing A Blue chromatizing B Yellow chromatizing C Olive chromatizing D yellowish lustre to yellow-brown iridescent (standard) olive-green to olive-brown (rare) BK blackish brown to black (decorative) Black chromatizing1) transparent, with a tinge of blue Nominal thickness ot the coating µm 3 5 8 3 5 8 3 5 8 3 5 8 3 5 8 First appeariance of: White rust, hours Red rust, hours Std. Std. 2 12 6 24 6 48 6 12 12 36 24 72 24 24 48 72 72 120 24 24 72 96 96 144 — — 12 — 24 72 On edges, the edges of the Phillips recess etc. use of the drum process means that you can practically always expect the black chromate coating to be rubbed off here and the underlying light-coloured zinc coating to become locally visible. 1) Reduction of the risk of hydrogen embrittlement (ISO 4042) There is a risk of failure due to hydrogen embrittlement in galvanically finished fasteners which are under tensile stress and which are made from steels with tensile strengths of Rm ≥1000 N/mm2, corresponding to ≥320 HV. However it cannot be guaranteed that the risk of hydrogen embrittlement will be removed completely. If the risk of hydrogen embrittlement must be reduced, then other coating procedures should be considered. Heat treatment (tempering) of the parts, e.g. after the acid pickling or metal coating process, will reduce the risk of breakage. Alternative methods of corrosion protection or coating should therefore be selected for parts which are important to safety, alternatives such as anorganic zinc coating, mechanical galvanization or a switch to rust- and acid-resistant steels. Where the method of fabrication allows, fasteners in classes ≥ 10.9 (≥ HV320) are provided with an anorganic zinc coating or are mechanically galvanized. The user of the fasteners knows the purposes and requirements for which the fasteners are to be used and he must specify the appropriate type of surface treatment! www.bossard.com T.026 © 2005 by Bossard Home e and f tolerance are not common and require special methods of screw manufacture. External threads are normally fabricated intolerance zone 6g.5 3 3. An alternative is to use parts made from stainless steel A2. 22) 24 (27) 30 (33) 36 (39) 42 (45) 48 (52) 56 (60) 64 µm +17 +18 +18 +19 +19 +20 +20 +21 +22 +22 +24 +26 +28 +32 +34 +38 +42 +48 +53 +60 +63 +71 +75 +80 max. How ever. The determining characteristic is the thread pitch. length l Overall viation ≤ length 5d 10d 15d µm µm µm µm µm – 50 – 53 – 56 – 56 – 60 – 60 – 63 – 67 – 71 – 71 – 80 – 85 – 90 – 95 –100 –106 –112 –118 12 12 12 12 15 15 15 15 15 15 20 20 20 20 25 25 25 25 12 12 12 12 15 15 15 15 15 15 20 20 20 20 25 25 25 25 10 10 10 10 12 12 12 12 12 12 15 15 15 15 20 20 20 20 8 8 8 8 10 10 10 10 10 10 12 12 15 15 15 15 15 15 Information for coarse pitch threads is given for information. 3) Maximum values of nominal coating thickness if batch average thickness measurment is agreed. 1.2) 3 3.2 0.3 0.25 0. Possible solution: Use of a chemical nickel plating or stainless steel screws A2 or A4. This can cause assembly problems. length l Overall viation ≤ length 5d 10d 15d µm µm µm µm µm –34 –34 –35 –36 –36 –38 –38 –38 –40 –42 –45 –48 –52 –58 –63 –70 –75 –80 –85 –90 –95 8 8 8 8 8 8 8 8 10 10 10 12 12 12 15 15 15 20 20 20 20 8 8 8 8 8 8 8 8 10 10 10 12 12 12 15 15 15 20 20 20 20 5 5 5 5 5 5 5 5 8 8 8 8 10 10 12 12 15 15 15 15 15 5 5 5 5 5 5 5 5 5 5 5 8 8 8 10 10 12 12 12 15 15 Tolerance position e Nom. Funda2) 3) mental deNom. longer delivery periods and higher prices may make these economically unviable. Maximum values of nominal coating thickness if local thickness measurement is agreed. coating thickness max.4 1.25 1. Minimum quantities. length l Overall viation ≤ length 5d 10d 15d µm µm µm µm µm –17 3 3 3 3 –18 3 3 3 3 –18 3 3 3 3 –19 3 3 3 3 –19 3 3 3 3 –20 5 5 3 3 –20 5 5 3 3 –21 5 5 3 3 –22 5 5 3 3 –22 5 5 3 3 –24 5 5 3 3 –26 5 5 3 3 –28 5 5 5 3 –32 8 8 5 5 –34 8 8 5 5 –38 8 8 5 5 –42 10 10 8 5 –48 12 12 8 8 –53 12 12 10 8 –60 15 15 12 10 –63 15 15 12 10 –71 15 15 12 10 –75 15 15 15 12 –80 20 20 15 12 External thread Tolerance position f Nom. 1) 2) If no particular plating thickness is specified. this has no significance in practical use because when assembled these are protected by the coating of the external thread of the screw. position G thread 1) diameter Funda.5 6 1.5 0.5 4 4. Funda2) 3) mental deNom. µm 3 3 3 3 3 5 5 5 5 5 5 5 5 8 8 8 10 12 12 15 15 15 15 20 Tolerance position g Nom. coating thickness max.75 0.4 0.8) 2 2.5 (2. the minimum plating thickness is applied.027 © 2005 by Bossard Home .6 0. Measuring points for coating thickness Measuring point Measuring point www.45 0. Internal threads have a thinner coating due to technical reasons.5 5 6 (7) 8 10 12 16 (14) 20 (18.75 2 2.bossard.8 1 1.7 0. This is also considered the standard plating thickness.Coating thickmental deness viation d1 mm 0.5 1. In the case of parts with very long thread or small dimensions (≤ M4).5 5 5.2 1. Funda2) 3) mental deNom.com T. coating thickness max.Corrosion protection Coating thicknesses for parts with external thread according to ISO 4042 Thread pitch P Internal thread Nominal Tol.5 4 4. an irregular coating thickness may occur due to the processing.35 0.6 (1. steel components are brass-plated in order to improve the adhesion of rubber to steel.028 © 2005 by Bossard Home . Anodizing When aluminum is anodized (electrolytic oxidation). Property class ≥ 10. Thermal treatment must be carried out immediately after plating and before chromating. Dacromet (non-electrolytic) Dacromet is an excellent coating for high strength components with tensile strength of ≥ 1100 MPa (Hardness ≥ HRC 31. Copper-plating Used when necessary as intermediate coating prior to nickel-plating-chromium-plating and silver-plating. Tribological coating (Solid film lubricants) Waxing These coatings provide a friction reducing and wear resistant film. The pellets serve to transfer the zinc powder to the surface to be treated. Only slight corrosion protection. Better corrosion protection oiled. Color change possible after a certain time. of about 440 °C to 470 °C. Coating thickness about 0. Thickness of coating not less than 40 µm. see table below. Usually following nickel-plating. Chromium is decorative. Silver-plating Tin-plating Silver-plating is employed for decorative and technical applications. especially with screws. Drum chromium plating not possible. a coating which provides corrosion protection is produced – also prevents tarnishing.9). Used for decorative purposes. atramentizing) Waterproofing / sealing Particularly with nickel-plated parts.Further galvanic coating processes Corrosion protection Process Nickel-plating Details Nickel-plating is decorative and provides effective corrosion protection. Temperature resistant 300 °C. Black oxidizing Stainless steel Black oxidizing Chemical process. Improves protection against impregnation.com T. Threads need to be over or undercut to assure proper thread mating. Baking Following electrolytic or pickling treatment. enhances resistance to tarnishing and improves corrosion protection. Veralisation Chromium-plating A special method of hard nickel-plating. Matt chromium-plated: matt lustre (silk finish). Phosphate (bonderizing. Very good corrosion protection. Finish dull and rough. Corrosion resistance from A1–A4 may be low. Practically any color can be produced for decorative purposes. Polished chromium-plated: grinding. Subsequent heat treatment not possible. Significantly improves the corrosion resistance.bossard. high tensile strength steel parts (from 1000 Nmm2) can become brittle due to hydrogen absorption (hydrogen embrittlement). used in the electrical appliance and telecommunications industries. Brass-plating Brass plating is mainly applied for decorative purposes. subsequent treatment in dewatering fluid with the addition of wax may seal the micropores with wax. The wax film is dry and invisible. Bright chromium-plated: high brightness finish. Tin-plating is carried out mainly to permit or improve soldering (soft-solder). Experience indicates that this is not guaranteed 100%.4 µm. Reduce galling tendency. This process practically eliminates the possibility of hydrogen embrittlement. For decorative purposes. No coating abrasion occurs. A hard coating. Chemical process. bath temperature about 140 °C. Can be used for thread parts from M8. Provide a lubrication layer. Part of the hydrogen can be eliminated by baking between 180 °C and 230 °C (below tempering temperature). parkerizing. The degreased parts are placed in a drum with powdered zinc and glass pellets. merely slight corrosion protection. brushing and polishing of the surface prior to coating electrolytically (done by hand). Can be applied to size M4 and up. reduces driving torque and thread-forming screws. Grey to grey-black appearance. www. Simultaneously serves as corrosion protection. For decorative purposes. Mechanical plating Mechanical /chemical process. In addition. Good undercoat for painting. Further surface treatments Process Hot-dip galvanizing Details Immersion in molten zinc with a temp. This embrittlement increases for components with small cross sections. = 40000 N thread size M10 is found in column 2 (strength class 12.Q acting on the bolted joint. D Once the preload (force) has been estimated. eccentric axial force C The required maximum preload force FM max. A Select in column 1 the next higher force to the work force FA.029 © 2005 by Bossard Home . FA A 10000 N is the next higher force to FA in column 1. = 25000 N C 1 step for «tightening with manual torque wrench» leads to FM max. = 40000 N D for FM max. centrical axial force.9). The result should be checked mathematically in each case.8 M 3 M 3 M 3 M 4 M 4 M 5 M 6 M 8 M10 M12 M16 M20 M24 M30 M36 M 3 M 3 M 3 M 4 M 5 M 6 M 8 M10 M12 M14 M18 M22 M27 M33 M39 M 3 M 3 M 4 M 5 M 6 M 8 M10 M12 M14 M16 M20 M24 M30 M36 FA 1) VDI = Verein Deutscher Ingenieure www. 2 3 4 12. which is set and checked by means of dynamic torque measurement or elongation measurement of the screw – or 0 step for «turn of the nut» method or yield point controlled method.com T. The screw of strength class 12.9 will be assembled with a manual torque wrench.bossard. 1 or 1 step for either dynamic and centrical or static and eccentric force Example: A joint is loaded dynamically and eccentrically by the axial force FA = 8500 N. FA FA Force in N FA 250 400 630 1000 1600 2500 4000 6300 10000 16000 25000 40000 63000 100000 160000 250000 400000 630000 FA FA FA or 0 step for static.9 8. is found by proceeding from this number: 4 steps for static or dynamic trans- verse (shear) force FQ FQ or 2 steps for dynamic.9 Nominal diameter mm Property class 10.Selection of fasteners Estimation of screw diameters according to VDI guideline 22301) The following procedure allows a rough estimate to be made of the required screw dimensions for a particular screwed connection and temperature around 20 °C. B 2 steps for «eccentric and dynamic axial force» lead to FM min. in correspondence with the details in VDI 2230. B The required minimum preload FM min. the correct screw size is found next to it in column 2 to 4 underneath the appropriate strength class. by: 2 steps for tightening the screw with a motorized/pneumatic screwdriver which is set for a certain tightening torque or 1 step for tightening with a torque wrench/or precision motorized screwdriver. is found by proceeding from this force FM min. leading to general release of the screw thread from bending stresses. fatigue strength ± σA [N/mm2] 150 100 2 50 1 0 0 6 8 10 20 40 Grafik: VDI 2230. are suitable for increasing the fatigue strength of the screwed connections. adequate and above all controlled prestressing of the screws. all measures which can reduce the effective peak stresses or prevent combined loading (loading along more than one axis). overlapping internal thread and bracing the screw with the starter head. the notching is provided by the thread. www. Long rather than short screws. at the entry into the internal (mother) thread. through design which allows flexibility in the reduced shank c) reduces the danger of fatigue failure in the internal thread through rounded indentation and overlapping screw threads d) Danger of fatigue failure in jammed thread runout of the screw thread e) reduces the danger of fatigue failure compared with (d) through design which allows flexibility. In 90% of the cases the break occurs in the first load-bearing part of the thread. Other constructive measures which can increase the fatigue strength: Basically. 20% lower than for screws hardened and tempered at the end of the manufacturing process.Fatigue resistance Strength under dynamic load according to VDI 2230 Screws are notched components. screws with waisted shanks rather than screws with normal shanks. independent of the static loading! The fatigue strength of fine threads decreases with increasing rigidity and fineness of thread. Under conditions of changing load. this amounts to a fraction of the tensile strength.com T.bossard. In these cases the design must allows for the fatigue strength ± σA of the screws. pins or fitted shoulder screws to absorb lateral forces.9. then thread rolled [mm] thread diameter a b c d e f g Fatigue failure Fatigue failure Fatigue failure through hole possible blind hole a) Danger of fatigue failure in the internal thread as well b) reduces the danger of fatigue failure – in the internal thread through overlapping screw threads – in the first load-bearing part of the thread. fatigue fractures can occur in the screws. For hot-dip galvanized screws the fatigue strength is ca.030 © 2005 by Bossard Home . Ausgabe 1986 j Thread rolled then hardened and tempered (standard practice) k Hardened and tempered. f) as for e) but here the centre belt serves to reduce bending stresses in the screw thread. For fastenings of strength class 12. it can be up to 30% lower than for coarse threads. g) reduces the risk of fatigue failure through tensioning the belt against the bearing surfaces of the internal thread. 9 12.5 d.4 · d 1. Recommended minimum length of engaged thread without countersinking for the strength class of the screw 8.0 · d GMgAl9 Zn1 > 230 1.Recom.8 · d] 1) 1.4 · d [2.5 AlMg3 F18 AlMgSi1 F32 AlMg4.25 · d 1.3 · d] 1) 1.4 · d 1.2 · d] 1) GJL 250 (GG-25) > 220 1.0 · d Rm in N/mm2 S 235 (St37-2) 2C15 N (C15) E 285 (St50-2) S 355 (St52-3) 2C35 N (C35 N) C45 V 35Cr4 V 34CrMo 4 V 42CrMo 4 V Values in brackets are based on the formula from VDI 2230 (theoretical values) 1) For lengths of engaged thread above 1.0 · d 2 · d [3 · d]1) 1.com T.1 · d 1. ISO 965-1 defines the grades of tolerance for external and internal threads. from information provided by manufacturer’s. min.6 · d 1.0 · d [1. external or internal threads at the extreme tolerance limits can lead to the screw becoming jammed.9 · d 1.4 · d 1.25 · d [1.4 · d 1.6 · d] 1) 1.bossard. compliance with these will ensure a problem-free assembly of the screwed fastening. so that when tightening up there is no need to worry about any resulting enlargement which might mean that the threads would not grip.9 · d [1.2 · d [1. lengths of engaged thread Length of engaged thread in cut internal threads on components. www.5 · d] 1) 1.5 · d 2 · d [3 · d]1) 1.5 F50 > 180 > 180 > 330 > 330 > 550 > 550 2.0 · d [1.2 · d 1. in order to ensure adequate durability of the screwed connection.8 · d] Al 99.6 · d] 1 1.8 · d] 1) > 800 (heat-treated sturcture) 0.4 · d 1.3 · d] 1) 1.4 · d [1.9 · d [1. On the other hand. This means that special attention must be given to achieving the required minimum length of engaged thread.4 · d 1.6 · d 2.8 · d 0.4 · d 1.0 · d 2.1 · d] 1) 0.0 · d 1.6 · d 2.25 · d [1.5Mn F28 AluMg1 F40 1 AlZn MgCu 0. There is normally less flexibility compared with standard nuts.0 · d [1. then minimum lengths of engaged thread have to be defined which depend on the strength of the material from which the component is made.031 © 2005 by Bossard Home .9 · d] 1) 0. The following recommended values have been determined from practical trials.8 10. in many cases the internal threads on the components are less strong than standard nuts of the same strength class for the screws which are being used.25 · d 1.1 · d] 1) > 500 (ferrite / perlite structure) 0.0 · d 2.8 · d [0.4 · d 1.9 Component material with incised internal thread tolerance 6 g / 6 H coarse thread fine thread coarse thread fine thread coarse thread > 360 (ferrite / perlite structure) 1.0 · d [1. based on trail values M6 to M16 Where screws have to be screwed into internal threads and where full load-bearing capacity is required. Tightening procedures.5812) 3.4401 1. since otherwise the screwed connection may become loose as a result of settling effects.6020 0.5Mn F27 (AW-5083) AlZnMgCu 1. 1986 edition. Power-operated screwdriver When tightening using a power screwdriver. for steels the permissible limiting value of surface pressure can be up to 25% lower! www. The much higher limiting surface pressures are supported by experience gained in practice and should be checked for each specific case of application.4365.4980 2.62 3.5 Tensile Surface strength pressure2) Rm [N/mm2] PG [N/mm2] 370 260 500 420 800 700 1000 850 1200 750 500 to 700 210 500 to 750 220 390 to 540 300 150 600 250 800 350 900 400 1100 350 480 300 220 200 140 450 370 based on VDI 2230.10 X 10 CrNiMo 18 9 Titan. with proven limiting values The values given apply to holes without chamfers and with sufficiently large external diameter for the tensioned part at room temperature. 1) Boundary conditions which affect the surface pressure 2) Chamfer Chamfers at the hole (contact surfaces with the fastening element) can for steels result in permitted values for surface pressure up to 25% higher being achieved (supporting effect).4952 0.61 3.3547.05 3.2315. Materials for the locking parts St 37 St 50 C 45 42 CrMo 4 30 CrNiMo 8 X 5 CrNiMo 18.com T.0553 1.7720 1. Based on VDI 2230.2163.7165.7060 3.08 3. edition of 2003 with typical values determined experimentally Abbreviated term for the material EN designation USt 37-2 (S235 JRG1) St 50-2 (E295) St 52-3U (S355 JO) Cq 45 34 CrMo 4 34 CrNiMo 6 38 MnSi-VS 5-BY 16 MnCr 5 X5 CrNi 18 12 X5 CrNiMo 17 12 2 X5 NiCrTi 26 15 NiCr20TiAl GG-25 (GJL-250) GGG-40 (GJS-400-15) GGG-50 (GJS-500-7) GGG-60 (GJS-600-3) AlMgSi 1 F31 (AW-6082) AlMgSi 1 F28 AlMg4.5 DG MgAl 9 GK MgAl 9 AlZnMg Cu 0.1192 1.71 3.02 3.62 (3.7050 0.Surface pressure when mounted Typical values for surface pressures for different materials The surface pressure in the bearing surfaces following tightening up the screw or nut should not be exceeded.2163.2315.7131 1.6582 1. supporting effects or the behaviour of anisotropic materials can often mean that a significantly higher value for pressure can be permitted than the pressure liquid limits for the particular material.2371.032 © 2005 by Bossard Home .0050 1.5231 1.10 Tensile strength Rm min.7040 0.5 (AW-7075) GK-AlSi9Cu3 GD-AlSi9Cu3 GK-AlSi7Mg wa AZ 91 TiAl6V4 Material number 1. unlegiert GG 15 GG 25 GG 35 GG 40 GGG 35.0036 1. [N/mm2] 340 470 510 700 1000 1200 900 1000 500 510 960 1000 250 400 500 600 290 260 260 540 180 240 250 310 890 Surface pressure1) 2) PG [N/mm2] 490 710 760 630 870 1080 810 900 630 460 860 700 900 700 900 1000 260 230 230 410 220 290 380 280 890 * Figures in italics have not yet been checked against the latest results from research and practice (TU Darmstadt).4303 1.bossard. 81 34.5 90 130.7 mm2 8.3 28.9 55.5 6.4 337.8 385 528 364 442 405 308 580 454 517 418 515 541 532 480 637 528 576 520 10.6 26.5 10 13 16 18 21 24 27 30 33 36 40 45 mm 6.33 17.4 mm2 8.8 250 268 292 333 331 478 452 447 482 474 473 447 530 470 10.5 17.8 89.78 14.6 28 42.8 464 638.3 576.1 211.5 15.6 9 11 13.1 94.9 11.1 36.17 23.4 19.53 8.5 20 22 24 24 26 30 33 mm2 11.6 38 42.03 9.17 25.1 74.64 20.5 17.3 84. R M 4 M 5 M 6 M 8 M10 M12 M14 M16 M18 M20 M22 M24 M27 M30 Ø of head dK dk Nominal thread Ø d The values shown in the tables for surface pressure are for a 90% utilisation of the yield strength of the screw Rp0.6 58 58 84.6 114.1 188.12 (reference: 2003 edition of VDI 2230).3 141.6 14.9 568 777 532 649 594 452 853 668 759 613 756 769 761 685 908 750 821 740 12.2 20.bossard.2 31. dw Nominal thread Ø d dh > da Surface pressure under the head of a cheese head screw with hex socket to DIN 912 (ISO 4762) and coarse thread Stressed crosssection As mm 7 8.3 115 115 157 192 245 303 303 353 459 561 Surface pressure under the head 1) N mm2 [ ] 8.6 244.87 28.61 43.61 mm 4.5 15.9 34.63 15.63 17.5 5.5 15.com T.9 665 909 625 761 695 529 999 782 888 718 885 901 888 803 1065 880 960 865 d Through hole (ISO 273) dh dh Ø of the bearing surface dW min.Surface pressure when mounted Surface pressure under the head of a hexagon screw DIN 931 / 933 (ISO 4014 / 4017) with coarse thread Bearing surface Ap Stressed crosssection As mm 7 8 10 13 16 17 18 19 21 22 24 27 30 34 32 36 41 46 mm 5.5 342.3 420.1 73.7 mm 4.6 16.9 8.5 5.1 36.3 115 157 192 245 303 353 459 561 Surface pressure under the head 1) N mm2 [ ] 8.38 12.2 20.71 30 33.87 31.033 © 2005 by Bossard Home . 1) www.6 58 84.5 20 22 24 26 30 33 mm2 17.3 254.8 181.5 6.2 and µG = 0.23 20.1 96.33 15.5 22.81 38.4 157.5 25.6 9 11 11 13.9 432 461 502 574 567 822 776 767 804 791 792 744 884 782 dw Bearing surface Ap dh Through hole (ISO 273) dh d Ø of the bearing surface dW min.5 274.4 13.9 6.8 427. da M 4 M 5 M 6 M 8 M10 M10 M12 M12 M14 M14 M16 M18 M20 M22 M22 M24 M27 M30 Width across flats s max.9 370 394 427 489 485 702 663 656 686 678 675 635 756 669 12.5 355.79 14.5 13. bossard.com T. – through hole to ISO 273 – select a thin one Advantages of flange screws and flange nuts: – less intrusion – clamping force in the fastening during mounting tends to remain stable – flange products are more economic than large washers under normal screws and nuts (fewer fastening elements and quicker assembly) – flange screws and nuts allow greater hole tolerances and so are more economically efficient.9 ≤6 8 9 10 12 [N/mm2] 100 HV 320 yes no no no no yes no no no no 200 HV 640 yes yes no no no yes yes no no no 300 HV 965 yes yes yes yes no yes yes yes yes no yes yes yes — yes — 200 to 300 300 to 500 500 to 800 Limiting conditions such as strength of component. The following measures can help reduce the surface pressure: – use of flange screws and flange nuts – chamfered holes. The effect of the production process. alignment of fibers and operating temperatures must be considered when making the selection.9 12. Field investigations have shown up to a 20% increase in permissible surface pressure.034 © 2005 by Bossard Home .8 10. www. surface finishing and temperature changes all play a decisive role.8 9. allowing for different strength classes (hardness classes) Screws Hardness class Assigned tensile strength Property class Nuts Property class Washers case-hardened.Surface pressure under the screw head Typical application Surface pressure when mounted It is not possible to precisely define the permissible surface pressure for a particular type of material used to make a component. the alignment of fibers in the material. – flange nuts have a better stability against shaking than normal screws and nuts. Guide to the use of flat washers for screws and nuts according to ISO 887 An overview of suitable combinations of flat washers with screws and nuts. thread-forming screws Stainless steel screws and nuts Surface pressure permitted values [N/mm2] ≤ 6. surface structure. production process.8 8. Zn/Fe hot-dip galvanized galvanised coatings such as none Zn/Fe.1 0.28 0. Zn/Fe. galvanized coatings such as or in pastes Zn. as-delivered condition hot-dip galvanized MoS2. for screw connections according to VDI 2230 (the data in the table is valid at room temperature) Tightening torque MA [Nm] For a safe and secure mounting it is important to define the conditions for friction very precisely and to restrict their variations as much as possible. Zn/Fe. e.06 – 0.3 0. µK display variations since they are dependent on several factors.) and the method of lubrication (with/with- out oil. µG.9 µ 0.24 D 0. graphite.2 m ax FM max. PA. Zn/Ni wax glazes.30 Approximate values for static coefficient of friction µT in the separation joint according to VDI 2230 Combination of materials steel – steel / cast steel steel – grey cast iron grey cast iron – grey cast iron bronze – steel grey cast iron – bronze steel – copper alloy steel – aluminium alloy aluminium – aluminium min . If there is a large variation the desired prestress force can vary considerably.14–0.18 0. PE. zinc laminated coatings wax dispersions. Static coefficient ofefficient in dry state lubricated state 0. Zn/Ni wax glazes. molybdenum disulfide. In contrast to this the normal range of tolerance for the tightening torque has only a limited effect. 0.g.1 – 0. bright-polished solid lubricants such as black tempered MoS2.08–0.com T.23 0. PTFE.2 0. 0. anti-friction coating etc)! The following tables give friction coefficients for threads and for bearing surfaces. bright-polished solid lubricants such as black tempered MoS2.21 www. graphite. pastes austenitic steel wax dispersions. greases Al and Mg alloys oils.16 0. the quality of the surface finish (depth of roughness). PA.28 0.07 0.12 – 0. bright-polished as delivered state (lightly oiled) phosphated galvanic coatings such as none Zn.12 – 0. galvanized coatings such as or in pastes Zn.28 0.12 0. class Prestressing force FM [kN] Relation of firction coefficient classes to guidline values for various materials / surfaces and types of lubrification.035 © 2005 by Bossard Home . Rp Rp µm in. .24 0. blackened. etc.05 – 0. Zn/Ni zinc lmainated coatings adhesive austenitic steel oil galvanic coatings such as none Zn. the material combinations.18 0. Zn/Ni austenitic steel Al and Mg alloys FM min.2 0. min . Zn/Fe.20–0.bossard.10 Typical examples for: Material / surfaces Lubrification metallic. zinc laminated coatings wax dispersions metallic. galvanically zinc coated.15 – 0. molycoat paste.35 E ≥ 0. pastes metallic.15 – 0.1 – 0. Pl phosphated in lubricating lacquers.04–0. dachromatized. A range for µG and µK MA min. Friction coeff.2 0. the surface treatment (naked. Pl phosphated in lubricating lacquers. PTFE. graphite wax dispersions organic coatings with integrated solid lubrificant or wax dispersion austenitic steel solid lubricants or waxes.Friction and friction coefficients The friction coefficients µGes. PE.07 – 0. MA max. B C 0. g.com T. Tightening method Setting procedure Comments Yield-point controlled tightening.5 to 4 ±43% to ±60% Lower values for: – small rotation angles. The same applies to cases involving hard screws with short grip lengths and for quick tightening methods. MA min.2 0.. required prestress force in αA = assembly FM min. low variation in the output torque (e. .e. even simple modern torque screwdrivers are able to provide torques to very close tolerances. Lower values for: – large number of settings trials (post-torque) – on the horizontal axis of the screwdriver characteristics – play-free impulse transmission Surface: Tensioned part. – torque controlled tightening methods react to the effects of friction.bossard. ax m min . for impact screwdrivers and in hand assembly.4 Variation rFM 2 · FM middel ±9% to ±17% 1. αA therefore covers the variation in the desired prestress force in assembly between FM max. max. depending on the tightening factor. the screw dimensions are selected based on FM min. ±5 % ) is required. phosphated surfaces or surfaces with adequate lubrication higher values for (at): – large rotation angles.g. for cases involving soft screws and in tightening methods which are slower. ±9% to ±17% rotation-angle controlled tightening. as e.g. possible prestress force in assembly FM max. min .4 – tightening method with measurement of extension – hydraulic tightening methods are practically independent of friction. Setting of the wrench based on post-torqueing. Lower values for: measuring torque wrench – consistent tightening – precision screwdriver tightening with impact wrench or impulse wrench. Experimental determination of the pre-tightening and rotation angle (in stages) The variation in the prestress force is largely determined by the variation in the yield point in the screws used. e. signal-emitting spanner or precision screwdriver with torque measurement. with the tightening factor αA.2 to 1.0 (friction coeffiecient class B) ±23% to ±33% torque-controlled tightening using a torque wrench. together Lower values for: signal-emitting with a rough surface torque wrench or torque wrench with release mechanism.. 1.2 to 1.6 bis 2.2 µ FM max. – relatively low stiffness of the surface1) – surfaces which do not tend to corrode. and inaccuracies in reading off values.Today. Determination of the desirable tightening torque made by estimating the friction coefficient (surface and lubrication conditions). lower values for long screws (lk / d ≥ 5) higher values for short screws (lk / d ≤ 2) 1. vary from ± 9% to as much as ± 60%. The design of the screw is based on the maximum tightening torque MA max.7 to 2. 1) www. operational failures. i.4 to 1. Experimental determination of the desirable tightening torque on original screwed connection component. Given value for the relative torque and turning angle coefficients. 1. so that the screw will not be overloaded during assembly. and FM min. either power-assisted or manual. relatively stiff connections. for this tightening method there is no screw design for FM max. 0.g. Maximum variations in Tightening factor aA 1.2 to 1.g. ±26% to ±43% 1. Here. Their αA factors are low.e.6 ±17% to ±23% torque-controlled tightening with torque wrench. The αA factors are generally higher: Smaller variations and so smaller αA factors occur for friction coefficients which have been derived from preliminary field trials. the tightening method. the equipment tolerances. relatively flexible connections and fine threads – high degree of stiffness of the surface. 0. by measuring the elongation of the screw. The tightening factor αA (a factor of uncertainty in assembly) allows for errors in estimating the friction coefficients. e. Lower values for: a large number of settings and control tests (e. derived from the desirable tightening torque (for the estimated friction coefficient) plus an additional allowance. min.5 (friction coefficient class A) 2. The tightening factor αA is then defined as: Tightening method tightening factor aA Prestressing force FM [kN] Guideline values for the tightening factor aA andteh resulting prestress forces in assembly (according to VDI 2230 – 2001) Tightening torque MA [Nm] Higher αA factors arise where friction coefficients are estimated. torque over a range of ± 2% are typical values quoted by manufacturers. Rp Rp µm in.9 FM min. 20) are necessary. signal-emitting spanner or precision screwdriver with torque measurement. i. Setting based on measurement of lengths and applied pressure. MA max.036 © 2005 by Bossard Home . the surface of which is in contact with the tightening element of the connection (screw head or nut).6 ±9% to ±23% hydraulic tightening. Nevertheless the resulting prestress forces in assembly. either power-assisted or manual. 3 ax . look for M12.038) Prestressing forces and tightening torques This procedure neither replaces the calculation as defined in VDI 22301) nor meets the current state of technology. Maximum permissible torque.14. tightening torque.8. 4 2 Tightening torque 5 MA [Nm] Control For installations with commercial.How to use reference values of preload and tightening torques (aus Tabellen T.2 limit). if fasteners are re-used (retightened). Users (engineers) ought to verify parameters to assure an adequate clamp load in the bolted joint. as used in the example.0 is adequate. using calculations as stated in VDI 2230 is highly recommended.14 – 0. with an estimated friction coefficient. lower friction coefficient µtotal = 0. To find the maximum preload.8 FM min. The calculations in VDI 2230 are state of the art Is the minimum preload FM min. The minimum possible preload FM min. possibly leading to a bolt fracture during assembly – Tightening tools are not as accurate as they should be. the resulting maximum preload FM will be lower as well.14. www.8» you will find the Maximum tightening MA max.036).com T.038 look for M12 in the thread column. The main reason for such fractures is that the actual friction is lower than anticipated. = 41. = 93 Nm.8 Minimum expected preload (clamp load) FM min.037 © 2005 by Bossard Home .035) αA Preload scatter Step 1: FM min. the maximum resulting preload MA max. from that torque FM max. one should use the lower friction coefficient. again leading to a premature bolt fracture either during assembly or in use. zinc plated. adequate for the intended application? Are surface pressures in the bearing areas brought in line with strength of clamped parts? How high is the residual clamp force when work forces are applied? Will the bolted joint be used in a manner not to exceed the fatigue limit? If one applies a tightening torque MA that is lower than the stated torque value in the table. a tightening factor aA of 2. start again in the thread column. which only requires a small torque angle. The minimum preload can be calculated by dividing the maximum preload through the tightening factor αA – see table on page T.036. finish. utilizing 90% of the specified yield strength (0.8 maximum preload FM max. In Table on page T. 90% yie of s ld s pec tren ifie gth d 1 in. FM max.bossard. We use a short screw (M12x40). = FM max.0 must be applied. / aA = 41. Possible reason for the torque to be different: – Friction is lower than anticipated.14 m Step 2: Fasteners used are electro zinc plated zinc plated µ Example: Friction coefficient µtotal 2) The exact conditions of surface roughness. Example: Friction coefficient µtotal = 0.038. therefore a lower tightening factor can be applied. FM [kN] µm Tightening torque MA max.24. move over into the left half of the table.9 kN Minimum preload FM min. Now move over to the right half of the table under «maximum tightening torque under property class 8. it will allow one to approximate a torque that does not cause a bolt fracture during assembly. uninterrupted fashion. To make sure the bolted joint is not over-tightened. then the fraction coefficient 0. and lubrication in the thread and in the under-head bearing are often not known. tightened in a uniform. Assumed tightening factor: αA = 1.9 kN / 1. Step 3: Example: Step 4: Example: Step 5: Hex cap screw per ISO 4017 M12x40 property class 8. To calculate the friction coefficient µtotal one can use DIN 946. For a signal type torque wrench. = 23. etc. the preload value can be found under property class 8. – Clamped parts are deformed unexpectedly (head embeds into material) Bossard engineering recommends using torque / tension equipment to verify specific parameters such as friction. clamp load. The values assume that one uses either precision torque wrenches or precision power drivers with a tool inaccuracy of maximum 5%. However. the friction is likely to be different than when the joint was initially tightened (VDI 2230 friction table on page T. in the friction column look for 0.3 kN Double checking values. Also. Maximum Preload FM max. This results in a relative stiff joint. is found in torque and preload tables starting at page T. (see table at page T. assuming same friction underneath the head and in the thread. modern torque wrenches. 1) 2) Bolt calculation guideline prepared by: The German Engineering association available in English and German Under head and thread friction combined. can be found in the same tables. a tightening factor αA = 1. would be affected as explained in step 4.6 – 2. 10 0. µges.1 20.2 91.4 39.58 0.4 29.83 5.54 2.2 37.4 139.6 36.4 189.73 0.1 21.32 2.9 80.050 0.9 27.8 2.51 5.1 37.93 0.42 1.95 3.2 9.2 5.1 101.95 4.4 3.10 0.2 3.4 117.14 0.36 1.6 45.23 5.024 0. Maximum prestressing FM max.1 192.10 3.2 6.87 4.1 52.70 0.5 88.5 17.7 21.1 202.9 8.00 2.4 3.6 61.7 18.1 5.2 42.8 12.2 4.8 1.2 9 10 11 18 21 23 32 36 40 4.14 0.6 2.8 8. [Nm] 0.14 0.7 135.3 10.5 4.4 269.12 0.18 2.89 1.48 2.6 28.8 10.4 20.8) 6.4 8.8 22.14 0.7 44.82 0. 8.2 46.051 0.17 2.7 6.4 42.15 6.6 20.3 4.42 3.0 50.7 210.1 30.6 4.3 13.6 54 79 27 34 55 73 108 31 39 62 84 123 34 43 69 93 137 44 55 88 117 172 50 62 100 133 195 55 69 111 148 218 67 84 134 180 264 76 96 153 206 302 85 107 171 230 338 93 117 187 259 369 106 133 212 295 421 118 148 236 329 469 131 164 262 363 517 150 187 300 415 592 167 209 334 464 661 176 220 353 495 704 202 252 403 567 807 225 282 451 634 904 226 282 451 625 890 257 322 515 714 1017 287 359 574 798 1136 331 414 662 915 1304 379 474 759 1050 1496 424 530 848 1176 1674 450 563 901 1246 1775 515 644 1031 1420 2033 575 719 1151 1597 2274 608 760 1216 1679 2392 697 871 1395 1928 2747 780 975 1560 2161 3078 783 979 1566 2164 3082 897 1121 1793 2482 3535 1002 1253 2005 2778 3957 1011 1264 2022 2791 3975 1160 1450 2321 3208 4569 1299 1624 2598 3597 5123 Typical values: The typical values are somewhat higher than in the earlier version of VDI 2230 / 1986.2.8 7.044 0.0 41.Prestressing forces and tightening torques M 1.2% elongation limit Rp 0.80 4.2 30.4 379.4 7.5 82.1 75.038 © 2005 by Bossard Home .2 53.46 4.14 0.3 135.19 1.76 0.6 28.032 0.5 138.98 3.22 1.91 1.57 7.1 69.9 for a 90% utilisation of the yield point Rel / 0.4 91.6 50 14.1 50.9 25.3 5.74 3.5 60 66 109 123 136 190 214 237 4.6 308.3 15.5 10.13 1.2 15.7 47.0 4.14 screws with similar strength heads and head bearing surfaces of strength classes 3.6 10.10 0.3 47.8 627 607 588 1039 1008 976 1725 1676 1625 2582 2510 2436 10.3 7.8 138.4 12.46 3.81 0.1 6.5 8.9 139.6 18.63 2.9 882 854 826 1461 1417 1373 2426 2356 2285 3631 3530 3426 12.1 11.2 111.1 32.6 9.5 9.10 0.14 1.1 16.0 262.7 13.2 197.3 25.26 1.4 17.82 3.0 13.7 15.5 35.10 0.1 5.67 0.10 0.4 4.94 2.1 16.1 389.6 60.3 12.4 26.0 142.bossard.6 1.0 21.89 4.2 120.5 31.97 3.59 3.3 131.2 7.9 14.10 0.12 0.9 18.33 1.14 0.9 17.5 21.8 9.7 12.7 44.6 (4.6 30.0 20.67 3.2 22.0 135.90 3.6 (4.12 0.21 1.028 0.36 3.1 6.51 2.4 114.09 1.2 61.7 7.10 0.3 60.0 58.4 98.0 105.14 0.12 0.8 104 102 99 134 130 127 166 162 158 192 188 183 252 246 240 307 300 292 381 373 363 448 438 427 537 525 512 6.8 32.12 0. This is because making an allowance for reserves which have not so far been utilised means that better use can be made of the screw strength through applying a higher prestressing force during assembly.8 49.9 82.3 40.3 52.9 5.6 44.8 68.6 3.1 43.3 44.3 16.7 6.68 2.8 10.5 13.53 2.7 324.12 0.0 The relationship MA = FM · X.5 28.12 0.0 81.51 1.9 78.12 0.9 12.3 26.5 6.4 1.3 16.8 103.10 0.3 27.6 59.12 0.6 4.8 176 235 294 470 171 228 285 455 165 220 275 441 292 390 487 779 283 378 472 756 274 366 457 732 485 647 809 1294 471 628 785 1257 457 609 762 1219 726 968 1210 1936 706 941 1177 1883 685 914 1142 1827 Maximum prestressing FM max.044 0.7 4.94 2.7 7.5 43.040 0.37 2.8 44.3 18.5 19.2 20 23 26 33 37 41 50 57 64 70 80 89 98 112 125 132 151 169 169 193 215 248 284 318 338 386 431 456 523 585 587 672 752 758 870 974 5.10 0.58 1.10 0.43 5.76 4.5 276. [kN] 1.17 5.0 27.0 65.58 2.4 121.1 18.06 4.1 12.7 84.9 57.3 96.3 40.8 31.3 7.5 243.4 43.3 37.8 6.12 0.0 32.035 0.1 145.17 2.9 237.0 31.48 2.9 23.12 0.7 8.76 5.14 0.71 3.0 10.84 7.1 27.3 21.3 26.71 7.0 134.92 2.3 45.26 1.10 0.9 19.12 0.6 58.5 5.10 0.10 0.18 3.035 Threads The details are based on the 2001 edition of VDI 2230: Maximum permitted tightening torques and the resulting maximum prestressing forces for hexagon head screws to ISO 4014 – 4018.33 5.5 26 11.2 55 24 30 49 65 91 27 34 55 73 103 30 38 60 81 113 42 53 84 112 158 48 60 95 127 179 53 66 105 141 198 Maximum tightening torque MA max.7 168.5 12 13.7 108.1 34.3 173.8 316.8 3.8 14.86 0.65 1.9 86.8 94.22 1.037 0.4 31.8 5.90 3.4 12.32 1.9 2.1 11.9 8.031 0.4 131. [Ncm] Property class based on ISO 898 / 1 Property class based on ISO 898 / 1 5.14 0.7 158.7 118.5 36.6 7.0 10.14 0.12 0.3 370.2 2.6 31.3 14.14 0.5 49.4 75.0 11.0 86.3 22.3 36.9 73 83 93 126 144 160 201 229 255 309 354 395 432 492 549 605 692 773 824 945 1057 1041 1190 1329 1526 1750 1959 2077 2380 2662 2799 3214 3601 3607 4136 4631 4652 5346 5994 Conversion factor X Typical values for metric coarse threads 0.65 4.8 115.2 64.3 36.14 0.9 10.6 2.3 83.9 14.6 4.7 89.0 231. The table shows the permissible maximum values and does not include any additional factors of safety.1 16.0 16.12 0.65 1.1 75.14 0.10 0.9 4.1 71.3 14.9 8.6 71.8 7.0 32.14 0.10 0.9 194.4 115.1 57.14 0.3 43 63 18.058 0.7 222. hexagon socket head screws to ISO 4762 and for 0.5 32.9 8.0 58.8 63.9 36.3 16.4 11.9 1058 1025 992 1754 1701 1647 2911 2828 2742 4357 4236 4111 3.7 35.6 15.0 13.6 13.10 0.2 8.12 0.5 79.0 29.8) 6.7 5.94 2.2 108.3 11.5 28.9 38.26 4.0 172.14 0.41 5.7 45.2 24.9 1.14 0.0 104.1 10.7 84. It assumes the user is familiar with the appropriate guidelines and design criteria.0 72.4 174 170 165 223 217 212 277 271 264 320 313 305 420 410 400 511 499 487 635 621 605 747 729 711 895 875 853 0.5 98.12 0.6 1.4 65.19 3.0 138.1 21. 12.8 185.14 0.1 8.12 0.9 142.2 7.3 7.7 23.6 to 12.3 4.5 86. can be used to calculate the tightening torque for every other value of prestressing force.2 114.0 4.5 121.1 14.10 0.74 2.11 7.0 17.3 15.6 162.25 3.9 60.0 10.9 22.5 48 71 20.02 Calculations toprove this are required! VDI 2230 – 2003 www.7 26.63 4.26 2.9 16.com T.12 0.8 57.3 118.6 3.0 11.10 0.20 6.10 0.7 35.8 5.0 111.2 178.10 0.5 28.4 66.2 45.94 2.8 67.7 73.6 154.6 M 2 M 2. see T.4 10.7 149 145 141 190 186 181 237 231 225 274 267 260 359 351 342 437 427 416 543 531 517 638 623 608 765 748 729 7.0 182.4 131.5 2.5 8.31 5.6 8.99 1.0 6.2 11.7 4.4 19.67 6.21 1.1 22.2 48.3 29.0 101.7 13.12 0.9 23.74 3.6 16.5 M 3 M 4 M 5 M 6 M 8 M10 M12 M14 M16 M18 M20 M22 M24 M27 M30 M33 M36 M39 Friction coeff.0 16.9 74.0 6.1 60.2 164.04 3.06 2.12 0.97 1.14 0.14 0.3 216.8 73.7 42.65 2.4 42.12 0.5 3. [N] Maximum tightening torque MA max. see page T.25 M14 x 1.12 67800 220 0.10 97800 320 0.6 131.8 68. This is because making an allowance for reserves which have not so far been utilised means that better use can be made of the screw strength through applying a higher prestressing force during assembly.12 0.5 M16 x 1.2 92.8 33. [Nm] Nuts MA max.10 0.7 34.bossard.6 20.2 29.8 45.8 1.5 M12 — 6.8 10. Calculations to prove this are required! VDI 2230 – 2003 Double-end studs with reduced shank (DIN 2510 L sheet 3) from steel 21 CrMo V 5 7 Typical valures for prestressing foreces and tightening torques used in assembly and at 70% of the minimum yield point (0.5 114.1 M4 0.10 0.5 46.14 0.0 70.6 at 20 °C after storage in a normal climate (relative atmospheric humidity in accordance with DIN 50014) until the moisture stability has been reached.10 0.10 6800 190 0.5 0.035.12 97800 370 M6 0. [Nm] M3 0.2 42.9 33.9 120 171 200 117 167 196 115 163 191 151 215 252 148 211 246 144 206 241 186 264 309 182 259 303 178 253 296 213 304 355 209 297 348 204 290 339 For an explanation of the friciton coefficient µges.9 20.2 52.5 M22 x 1.9 32. The table does not include any factors of Prestressing force FM max.12 0.6 128.7 150.10 0.4 66.10 0.8 – 12.6 85.5 M18 x 1.14 0. Threads Screws MA max.6 154.3 30.5 39.10 43500 98 M20 15 M24 18 0. Tightening torque MA max.7 28.9 49.1 38. The prestressing force can ease off as a result of relaxation processes.12 0.10 0.12 0.039 © 2005 by Bossard Home .14 0. [kN] Property class based on ISO 898 / 1 8.9 for a 90% utilisation of the yield point Rp 0.12 21600 44 0.1 44 65 76 51 75 87 57 83 98 79 116 135 90 133 155 101 149 174 124 182 213 142 209 244 159 234 274 189 278 325 218 320 374 244 359 420 283 403 472 327 465 544 368 523 613 392 558 653 454 646 756 511 728 852 529 754 882 613 873 1022 692 985 1153 666 949 1110 769 1095 1282 865 1232 1442 Typical values: The typical values are somewhat higher than in the earlier version of VDI 2230 / 1986.1 64. 1) safety and assumes the user is familiar with the design criteria.5 82.0 87.9 12.9 22.5 3.14 of strength classes 8.1 0.6 Typical values for advisable tightening torques for screws made from polyamide 6.7 89.10 0.10 0.25 0.12 0.7 30.1 84.4 97.1 72.8 0.12 43500 115 0.4 48.8 95.8 10.8 50.3 44.2 111.12 0.7 19.25 M12 x 1.6 46.14 0.25 M5 0.4 47. [Nm] Property class based on ISO 898 / 1 8.4 63.12 0.8 M10 3.Prestressing forces and tightening torques Typical values for metric fine threads The details are based on the 2001 edition of VDI 2230: prestressing forces and tightening torques for headless screws Threads M 8x1 M10 x 1.6 31.14 0.0 M16 — 12 Polyamide 6.12 0.5 146.5 0.5 55. FM [N] MA [Nm] M12 8.4 54.12 0.4 35.9 108.2 26.7 80.2.5 125.1) 0.8 M8 1.9 12.10 21600 38 M16 12 0.5 M24 x 2 µges.14 0.10 0.14 0.9 29.2 limit) Coarse thread Shank-Ø µges.14 0.5 www.5 M20 x 1.com T. 1 0.9 25.8 72.2 0.3 0.3 88.3 0.1 0.7 55 73.3 20.4 20.2 25.15 0.4 96.8 0.97 3.8 10.36 0.2.Preload and tightening torques Screws made from austenitic stainless steel A1 / A2 / A4: maximum permissible preload and tightening torques at 90% utilization of yield point Rp 0.3 Tightening torque MA [Nm] Property class 50 70 80 81 174 232 122 260 346 144 308 411 114 224 325 173 370 494 205 439 586 148 318 424 227 488 650 272 582 776 187 400 534 284 608 810 338 724 966 275 421 503 374 571 680 506 779 929 651 998 1189 842 1300 1553 Fasteners made from these steels tend to erode during fitting.1 0.6 0.75 10.12 2.2 0.5 1 2.5 27.3 0.1 0.5 5 10 ISO 7379 DIN 7991 ISO 14581 DIN 7991 ISO 7380 BN 6404 ISO 7380 ISO 4029 / DIN 916 12.2 0.2 0.1 0.9 2 3.1 0.3 1.5 M 3 M 4 M 5 M 6 M 8 M10 M12 M14 M16 0.3 15.7 2.8 2 6 9 20 40 65 110 180 1 4 5 12 24 40 66 110 1 2 4 8 12 35 50 A2-70 A4-70 0.9 6.5 0.3 0.75 0.96 1.2 0.49 5.1 0.24 1.2 56.1 0.8 6.6 M 2 M 2.3 0.2 0.26 4.5 4.45 0.25 1.85 9.7 78.85 0.2 32.3 0.7 1.09 4.9 59.47 1.4 0. low number of revolutions of the screwdriver.8 11.9 10.4 28. M 1.2 0.8 5.9 1 0.4 4 0.59 2.1 0.5 1.2 0.9 2.3 0.3 2.4 5.8 2 3.1 33.2 0.8 1.2 0.5 60.4 0.55 0.2 0.85 11 9. This risk can be reduced through smooth.4 13.3 0.8 A2-70 A4-70 0.39 2.54 7. or continuous tightening without interruption (impact screwdriver not recommended).2 0.6 29.45 0. [Nm] ISO 4026 / DIN 913 ISO 4027 / DIN 914 Screw type ISO 4028 / DIN 915 DIN 6912 Gewinde M 3 M 4 M 5 M 6 M 8 M10 M12 M14 M16 M18 M20 M22 M24 DIN 7984 8.5 0. 1) www.3 50 107 143 41 88 118 34 72 96 58 142 165 47 101 135 39 83 110 75 61 50 91 75 61 114 94 76 135 110 89 162 133 108 Threads µges.98 5.65 0.58 16.6 0.6 1.7 6.86 12.93 5.35 0.1 45.3 0.1 0.2 74.1 79 106 56 119 159 66 141 188 56 121 161 86 183 245 102 218 291 Preload FM [kN] Property class 50 70 80 32.6 0.4 0.1 0.25 0.3 26.8 0.4 0.1 0.6 0. Fasteners with hexagon and hexalobular socket and flat heads Maximum tightening torques MA max.1 1.1 0.2 25.com T.2 0.65 0. see T.3 44 58 24 51 69 23.08 2.2 0.2 0.2 0.1 17.1 8 2.035.6 16.2 0.4 0.3 0.9 44.5 0.9 8.7 40 53.14 13.3 0.5 33.55 0.2 0.45 0.1 0.3 0.95 0.2 0.9 8.2 0.7 4.7 31.1 8.85 8.6 9 19.25 0.1 0. molykote smooth varnish coating (black).2 6.5 3 4.2 69 92 26.9 13.6 Threads µges.4 0.35 0.5 1 2 4 6 15 30 45 H1) 0.1 0. lubricants.35 1.2 13.1 0.1 6.6 0.2 0.3 0.1 0. M18 M20 M22 M24 M27 M30 M33 M36 M39 0.4 3.6 0.3 0.19 4.49 3.6 0.3 1 1.5 19.2 0.040 © 2005 by Bossard Home .2 21.3 0.6 3.3 0.6 18.13 2.7 11.4 48.8 1 2 4 8 12 30 60 1 2 4 8 12 A2-70 A4-70 0.2 0.32 20 26.8 11. clean thread sufaces (rolled threads).4 4.1 23.6 7.35 0.25 0.4 0.3 0.9 1 1.3 0.5 5 7 21 30 110 66 280 170 200 120 390 235 BN 1206 BN 9524 10.1 0.9 8 4. part 5 are valid for headless screws not subjected to tensile forces.85 6.59 5.bossard.1 0.5 5 10 22 22 45 70 70 110 110 The mechanical characteristics and property classes according to ISO 898.9 1.5 8 20 33 50 55 4 9 25 40 70 1 2 5 9 200 1 2 5 9 15 40 65 100 110 400 150 75 400 200 10. For coefficients of friction.5 13.3 0.6 118.2 0.3 0.2 0.6 1.65 0.2 2.6 3.7 41.6 50 67 34.1 1.9 21.6 3.1 38. Preload FM [kN] Property class 50 70 80 0.3 0.3 0.7 30 39.1 21.83 3.6 2.94 2.3 0.2 0.1 0.4 12.3 0.1 0.5 5 10 18 8.2 0.8 A2-70 A4-70 8.25 3.8 14.7 1 1.2 0.8 74 100 41 88 117 37.1 0.2 0.5 1 3 5 10 20 45 45 90 140 140 220 220 A2 A4 0.85 0.8 4.5 1.1 0.4 58.45 0.6 0.2 0.4 35.3 Tightening torque MA [Nm] Property class 50 70 80 0.5 2.8 17 36.3 10.6 43.25 0. 4 2.2 2.16 10 18 37 80 120 215 310 0.6 3.5 BN 5128 BN 10649 4.7 8.6 1.4 6 M8 11 — 1.13 to 0. The inner and outer actuation of these screws permits only reduced tightening torques to be used.5 0.8 A2 M2.6 0.16 to 0. at a 90% utilisation of the elongation limit Rp 0.5 Tightening torques MA max.2 37 54 74 102 9 12.3 0. at a 90% utilisation of the elongation limit Rp 0.7 2.Prestress forces and tightening torques Locking screws and nuts. Check the boundary conditions! www. M5 M6 M14 M16 0.8 Guideline values*) The screws are not suitable for transferring high operating forces.8 1.2.9 M3 1 M4 2. flange screws and nuts based on manufacturer’s specifications Tightening torques MA [Nm] and achievable prestress forces FM [Nm] for VERBUS RIPP® screws and nuts and for INBUS RIPP® screws.125 to 0.14 to 0.5 1.35 Prestress force FM [kN] 16. [Nm] M8 M10 M12 Coefficient of friction for µges.2.com T. Classe Counter material Screws – Property class 100 Nuts – Property class 10 Steel Rm > 800 N/mm2 Steel Rm < 800 N/mm2 Grey cast iron GG tensile strenght Rm ca.18 11 19 42 85 130 230 330 0.8 A2 M3 0.8 5. Tightening torques MA for pan washer head screws with hexagon socket and pressed-on flange*) BN 11252 ~10.7 4.5 Tightening torques MA for eco-fix® hexagon screws with flange*) BN 5950 BN 5951 4. M5 M6 M14 M16 0. [Nm] Guideline values should be checked in field trials M5 M6 M8 5 8 21 M10 42 M12 72 Tightening torques MA for eco-fix® pan washer head screws with flange*) BN 4825 BN 5952 4.2 38. [Nm] Guideline values should be checked in field trials M4 M5 M6 1.4 M2.4 5 5.1 3.6 M6 0. Classe Counter material Screws – Property class 90 Nuts – Property class 8 Steel Rm ≈ 500 to 1000 N/mm2 Grey cast iron GG Rm ≈ 150 to 450 N/mm2 Tightening torques MA max.22 7 13 28 49 83 130 195 52. 150 to 450 N/mm2 Tightening torques MA max.16 9 16 35 75 115 200 300 Prestress force FM [kN] 23.5 26.3 9 Guideline values for achievable prestress forces should be checked in field trials.2 0.041 © 2005 by Bossard Home .6 Guideline values for achievable prestress forces should be checked in field trials. Tightening torques MA [Nm] and achievable prestress forces FM [Nm] for VERBUS TENSILOCK® screws and nuts.8 3. [Nm] Guideline values should be checked in field trials M3 M4 M5 0. [Nm] M8 M10 M12 Coefficient of riction for µges.5 Tightening torques MA max.22 9 16 34 58 97 155 215 0.4 — Tightening torques MA max.7 1.8 A2 0.16 to 0.2 M3 M4 M5 M6 3.5 73 6.bossard. bossard. part 4 for nuts DIN 6915 Washers DIN 6916. 6918 of steel hardened to 295–350 HV 10 The strength of high-strength structural steel bolts correspondsto the value stipulated in DIN 267. half the values of columns 3 to 5 and 8 or 9 and hand-tightening according tocolumn 6 is sufficient. an angle of rotation ϕ 360° and U = 1 must be used. parts 1. 6917. part 1 for bolts DIN 6914 DIN 267. design and manufacture of fasteners with high-strength structural steel bolts are regulated in DIN 18800.5 · FV. 1 2 Screw diameter Required preload FV in in the screw 3 4 Torque procedure 1 2 3 4 5 6 7 8 9 10 11 mm M12 M16 M20 M22 M24 M27 M30 M36 M12 to M36 kN 50 100 160 190 220 290 350 510 Tightenint torque MA to be applied lubricated with lightly MoS21) oiled Nm Nm 100 120 250 350 450 600 650 900 800 1100 1250 1650 1650 2200 2800 3800 5 6 7 8 9 Screw prestressed according to the Impact Angle of rotation procedure procedure Preload Pre-tightening Clamping Angle or rotation or to be torque to length number of revolutions applied be applied FM2) MA2) lk3) j2) U2) kN Nm mm 60 10 110 50 175 210 100 240 320 390 200 560 0 to 50 180° 1/2 see lines 51 to 100 240° 2/3 1 to 8 101 to 240 270° 3/4 Since the values MA are highly dependent upon the thread lubricant.Preload and tightening torques High-strength structural steel bolts according to DIN 6914 (HV sets according to DIN 6914 / 15 / 16) Dimensioning.042 © 2005 by Bossard Home . The screwsmay be tightened either by the nut or by the screw. – – – ISO 898.com T. torques and tightening angles. respectively ISO 898. shows the necessary preloads. For screws M12 to M22 with clamping lengths 171 to 240 mm. To apply a partial preload force ≥ 0. in which after having applied a certain preload. Table 1. which is taken from DIN 18800 part 7. 1) 2) 3) www. The following methods are available for applying preload to the bolt: – with hand operated torque wrench (torque process) – with power screwdriver which must be regulated to a well defined torque (angular torque) – angle of rotation process. observance of these values must be confirmed by the screw manufacturer. Does not depend on the lubrication of the thread and the contact surfaces of nut and screw. the nut or bolt is retightened with a well definedangel of rotation. Larger tolerance for hole-Ø.bossard. smooth joiint interfaces minimum number of interfaces No soft. = FV + FZ FV FQ lK SG d = preload = shear force = clamping length = displacement of clamped parts = nominal diameter The following locking methods are possible: Locking against loosening due to setting Locking against rotational loosening Measures Clean. plastically deformable joint members Long screws (lK > 4 x d).8. Screws with reduced shank Spring washers Fasteners with flange Effect achieved Reduction of setting possibilities.043 © 2005 by Bossard Home . Use up to strength class 8. www. Ribbed screws or ribbed washers. This will prompt screws and nuts to rotate. Measures Bigger screws Higher property classes Effect achiefed Lateral movement of the joint member can be prevented by a higher preload. Dynamic shear forces FQ acting upon the bolted joint can cause the joint members to slip back and forth. Rolling effect leads to compression of the surface with the embedding of the grooves. this reducing the preload until it is zero. FA SG FM fSM lK FV fpM FQ FV FQ FV FM min. High elasticity. Special washers with 200 HV hardness. The same advantages as above. compensation of preload loss. This loss is caused by setting of the joint members or by a permanent elongation of the screw after tightening or under the operation force FA. there are two reasons why bolted connections may need locking Loosening due to setting Rotational loosening Loosening of bolted joints results in preload loss.Summary of constructive measures for locking screw joints Securely fastened joints In principle. FZ d fZ FA FM = assembly preload fSM = elongation of screw through FM fPM = shortening of compressed parts through FM FV = final preload FZ = loss of prelaod due to setting = amount of setting fZ FA = operation force FM min. Shoulder screws Parallel or dowel pins No possibility for lateral movements A larger bearing surface prevents the permitted limiting value of surface pressure from being exceeded. Long screws (l > 4 x d) Flexible joint Screws with reduced shank Better fatique resistance.com T. 8 10.8 10. Thread-forming screws for thermoplastic materials PT® and DELTA PT® 3 1 1 Total security through formed. max. Precote type 30 / 80 / 85 1 Chemical thread locking adhesives eliminate thread play and provide a seal.9 For unhardened components. Prevailing torque nuts to DIN 982 / 985 etc. Designation of the part / Standard Screws and nuts with ribbed flange (VERBUS RIPP®) Screws and nuts with serrated flange (VERBUS TENSILOCK®) Serrated flange surface prevents unscrewing of unhardened components. 3 Castle nuts to DIN 935 etc. 5.9 div. 3 3 0 0 Spring washers to DIN 6796 etc. 1 3 Spring washer profiled on both sides with increased loosening torque with unhardened components. Ribbed washers (ribs on both sides) Cotter pin prevents loss. slight increase in the loosening torque. 5. unscrewing and/ or loss of screws are based entirely on field experience.com T. 0 Serrated lock washers and tooth washers to DIN 6798 / 6797 etc. Elastic nuts (Serpress®) etc. rotatable toothed lock washer. High loosening torque on soft bearing surfaces. ® 1 1 1 1 Screws with a polyaminide coating Tuflok® Thread-forming screws for metals DIN 7500 3 3 3 Total security through formed. 120 °C. 120 °C. Security against Loosening up to Rotational loosening up to Loss Comments div. 1 Protection against loss through polyaminide locking element. 0 Flange nuts / flange screws 3 good 3 3 Hexagon nuts with toothed lock washer (BN 1364) Locking effect: 1 very good Reduced surface pressure with larger friction area.6 8. although a limited amount of loosening is possible. 120 °C. 1 Increased loosening torque due to integrated.bossard. It is the responsibility of the user to check the various elements and methods based on his knowledge of exactly how they are to be used in each particular case. Prevailing torque nuts to DIN 980 / ISO 7042 etc. 0 3 0 Springy. Locking effect due to the elasticity (not locking).044 © 2005 by Bossard Home . Springy effect. 3 Hexagon nuts with spring washer 3 1 0 Spring washers to DIN 127 / DIN 128 / DIN 7980 etc.Securely fastened screwed connections List of additional ways of securing screwed connections and retaining collars against working loose or coming unscrewed Caution! The locking effects listed in the following table against loosening. 1 Protection against loss through sticky thread. 1 Screws with concave pan washer (eco-fix®) 3 Increased loosening torque due to the large concave pan washer. increased loosening 0 1 torque due to ribbed flange. Integrated spring washer compensates for setting. max. 3 0 moderate Screws which should be locked Grip length Lk Thread Ø d short Lk < 2 d medium 5 d > Lk ≥ 2 d long Lk ≥ 5 d Loading static in the direction of the axis transverse to the axis none none none dynamic in the direction of the axis transverse to the axis Clarify locking effect Clarify locking effect none Depends on the conditions clarify locking effect Locking required none Depends on the conditions clarify locking effect none Locking required www.6 8. play-free thread fitting. 3 ThreeBond. 1 Protection against loss through metallic locking element. High contact forces with corresponding spring characteristics. Sealing nuts with locking element (Seal-Lok®) etc. play-free thread fitting. profiled universal washer: increased loosening torque with unhardened components. max. DELO. 0 3 Rip-Lock® Profiled spring washers 1 Sealing and protection against loss through polyaminide locking element. bossard.5 7.5 9.4 3.9 3.9 5. [kN] from 10 mm nominal diameter 1 1.5 20 30 53 84 120 165 210 340 Dowel (clamping sleeves) light finish according to ISO 13337 up to 8 mm nominal diameter Nominal diameter.5 3.32 3.1 144.9 1.54 26. [kN] from 10 mm nominal diameter Material: spring steel hardened and tempered 420 to 560 HV 2 2.5 Material: 5 6 8 10 spring steel hardened and tempered to 420 to 560 HV 12 13 14 16 18 20 9.1 115.5 2 2.5 3 0.06 11.045 © 2005 by Bossard Home .5 3 3.4 0.5 4 5 6 8 10 12 14 16 20 0.76 70.com T.8 10.5 2 2.5 3 3.36 17. mm Shear force double lap joint min.45 2.8 1 1.Shear loads for pins Dowel pins (clamping sleeves) heavy finish Spiral pins.2 1. standard finish according to ISO 8750 Material: Nominal diameter.5 280. heavy finish according to ISO 8748 Material: Nominal diameter.5 5.6 15 22 39 62 89 120 155 250 Spiral pins.6 8 8.5 4 4.58 2.7 171 222. [kN] spring steel hardened and tempered to 420 to 545 HV 0. mm Shear force double lap joint min. heavy finish according to ISO 8752 up to 8 mm nominal diameter Nominal diameter.5 4 4.6 Spiral pins. [kN] spring steel hardened and tempered 420 to 545 HV 1. mm Shear force double lap joint min.24 15.4 18 24 40 48 66 84 98 126 158 2F Mt F F double lap joint www. mm Shear force double lap joint min.5 4.5 7.04 42.5 2.7 1.6 0.5 5 6 8 10 12 13 14 16 18 20 1.82 4.5 3 4 5 6 8 10 12 14 16 20 1.38 6.16 104.6 13.5 2 2. Resistance to vibration is provided by the thread friction. tolerance js 16 s = thickness of material The length of the cone-shaped end of the screw.Construction recommendations Direct screwed connections in metals using thread-forming screws according to DIN 7500 What should be considered in the design and construction processes? • Thread-forming screws to DIN 7500 (trilobular) produce a chip-free.5 x P 0. the use of punch holes can help improve the mechanical properties of the fastening. non-ferrous metals and light metals up to ca. A C s B A = cone-shaped end of screw.5 to 1x the thread pitch P or that you make a cylindrical countersunk hole. Die zylindrische Ansenkung hat den Vorteil.com T. • The screws are heat-treated to give a tensile strength in use of ca. which is not fully load-bearing. • Screws made from A2 stainless steel • • • • can only safely be screwed into light metals.) • Preliminary trials should be made for critical applications. It is recommended that preliminary trials be made for «laser-bored» holes (the cut surfaces may be to hard.bossard. 4 P B = usable thread length C = total length. In thin plates a through hole increases the load-bearing capacity of the fastening. • It is possible to form threads in ductile metals such as steel. max. Empfiehlt sich auch bei Druckguss. should be allowed for when deciding on the screw length. 800 N/mm2. 0. 140–160 HV.05 x Nenn-Ø min.5–1 x P Forming the pilot holes The displacement of the material which occurs when tapping the thread creates a small bulge at the edges of the tapping hole. This can create a problem when screwing smooth parts together. • Thread forming is not suitable for brittle metals such as grey cast iron. Functionally appropriate design of components and selection of the correct type of fastening element are essential requirements for a secure screw connection. Das bedeutet bei gleichen Materialien und Schraubendimensionen gleiche Montagemomente. dass durch das Anpassen der Ansenktiefe die Einschraubtiefe bei verschieden dicken Befestigungsteilenkonstant gehalten werden kann. Ask Bossard Engineering for more detailed information. 1. In doing this the size of the pilot holes must be 5% larger than the values in the table. No other safety features (such as retaining rings) are necessary. Get in touch with Bossard Engineering as early as possible in the development stage of your product. www. They can be re-used 10–20 times For thin sheets.046 © 2005 by Bossard Home . It is therefore recommended that you 90 °Countersink the edges of the tapping hole to a depth of 0. gauge-correct metric internal thread. 2 3.5 1.047 © 2005 by Bossard Home .04 0 M2.6 4.32 3.35 0.75 1.2 3.75 3.5 M6 1 M8 1.1 4 5.5 2.2 0.5 0 8 machines (delivery period ca. 135.65 4. d2.3 0.2 0 2. HB max.4 Diameter of tapping hole d – H11 for steel.5 0 0 0 3.76 0. • The speed should lie between 300 and 1000 rpm.23 3.75 3.5 3.4 M3. tensile force1) Thickness of material s mm Nm Nm kN mm 2 and smaller 4 6 8 10 12 14 M2. 1° α α d3 d2 blind hole Nominal thread diameter d11) d21) d31) 1) for d1. in order to allow for effects which have not yet been detected.2 0 3 What should you consider during assembly? • Secure and cost-effective fastenings can only be produced with screwdrivers which have controlled torque and/or turning angle. t2 1) M2 0.25 12 16 29 29 5.7 4.Construction recommendations Direct screwed connections in metals using thread-forming screws according to DIN 7500 Strength characteristics.65 4.36 2.2 2.06 0 5.86 2. centering of the screw.5 M4 M5 0. d3 t1 x 45° t22) 2) for t2 t3 Tolerance + – + Tolerance – mm mm mm mm mm mm mm mm mm mm M2 1.37 5.25 2. 80% of breaking torque 1.5 6 0.6 0.06 0 M3 2.and pneumaticallypowered screwdrivers can be used.25 7.5 as Bossard per supplier and test specification fillets which provide an advantage for die-cast metals strengthening of the mandrel.7 1.65 7.5 7.3 0.45 5.85 2.5 M4 M5 3. The automatic assembly of «standard stock screws» is not normally economically justifiable.8 ca.5 7.65 M3 0. • Both electrically.11 3.075 0. tightening torque min.7 0.3 3.4 7.5 5.7 3.075 0 0 0 variable. 10 to 16 weeks).com T.09 0 11 0.8 0.55 5.9 1.3 2.54 4.6 3.67 2. breaking torque1) min.5 2.6 0. geometry of tapping holes Technical details Thread pitch P max.48 0.77 3.4 7.2 0 2.55 2.6 0.075 0 M8 7. minimum 1 x thread pitch P 6.5 0.64 4.5 0.35 Nominal thread diameter M3.78 4.25 7.bossard.45 0.5 2. • If you want to assemble components using automatic screwing machines then get in touch with us as early as possible. so that we can define and have your screws manufactured to the required quality for automatic through hole M6 5. prevention of buckling of the material and adaptation to suit cost-effective standard screw lengths t2 / t3 [mm]: bearing part of the tapping hole.4 5.8 1.27 0.5 5.8 9.4 7 11.9 7. Calculating the torques see page T.24 7.7 4. taper angle α max.69 5.65 1 2.4 7.049 www. t1 d1 t3 General t1 [mm]: d1 t1 Tapping holes for die-cast metal All the recommendations must be tested by means of trial assemblies which closely resemble conditions in practice.2 3.5 4 5 • The repeatability of the accuracy of the screwing process should be checked in trials using building components.5 0 6 14 0. bored or punched 2.63 7.075 0. 048 © 2005 by Bossard Home . The design applies to all conventional plastics with a modulus of elasticity of up to E = 15000 N/mm2 (hole-Ø d for special plastics available on request): are subject to stress cracking. Lack of bearing surface can lead to the forming torque being greater than the head friction torque and this can make it impossible to construct a secure mounting.g.Construction recommendations Cost-effective connections The following example shows that.8 x d1 We recommend that control assembly runs be made using the first available parts. The 90° angle results in radial as well as axial relaxation.24 10. It is less dependent on the tube material and the length of engaged thread te.75 p te x 4 P parts made from plastic. The head friction increases the safety of the process du- ring assembly.24 1. through use of additives and fillers such as colour pigments and fibres. • Transverse forces should be taken up by the engagement between the components. a smaller surface pressure results in less relaxation and so in greater residual locking forces. The required screw depth for the Delta PT® screw can be calculated from the given depth of thread engagement AFL. In addition the Delta PT® screw offers all the following advantages: • New thread angle geometry with the main angle of thread of 20° favours the working of the plastic • Up to 50% more tensional and torsional strength for the same nominal Ø d1. and can also provide support through the use of DELTACALC® • Select larger head diameters (BN 20040) for fastening together parts made of plastic. which can transfer more prestress loading. e. It also ensures the even support of the clamping part. and where the edge distance is small this can lead to large losses in prestressing force.d2 ) x P mm 2. • Avoid using slot holes in clamping Shape of the hole The maximum achievable prestress force when overtightening is the criteria for determining the optimum hole Ø d. depending on the manufacturer.com T. Bulging of the plastic when forming the first turn of the thread. • Smaller Ø tolerances • Robust fastener. • Provide a pressure relief hole de (avoids stress cracks) D = 2 x d1 de te = 2 x d1 The Delta PT® has all the well-known properties of the PT® screw. 20 ° 140° • Increased stability against vibration thanks to the smaller thread pitch • Substantially increased working life for the connection. for the following reasons: • Processing conditions during manufacture of the plastic • Design of the injection moulding equipment • Position of the injection point • Creation of flow seams • Local texture.3 .88 x d1.46 d mm 4 4 3. and more dependent on the thread pitch P and the nominal diameter Ø d1 of the screw thread. Ask for informationon our «BossAnalytik» service. particularly with plastics such as polycarbonates which In practice deviations from these recommendations may arise.bossard. • Avoid using countersunk screws for clamping parts made from plastic.2 mm The pressure relief hole de is particularly important. A comparison of the Delta PT® with the PT® screw shows that: Use of the Delta PT® allows you to use a shorter and so more cost-effective screw. d = 0.42 11. thanks to the increased cross-section of the core 0.2 te mm 13. www. thanks to the smaller thread pitch P it is possible to design for a smaller length of thread engagement te. Construction recommendations • For simple fastenings the recommended published here are quite adequate • We would be pleased to help you with the design of fastenings under operational loadings. • The Delta PT® calculation program DELTACALC® allows a design based on prestress force in accordance with VDI 2230 PT® K50 Delta PT® 50 Delta PT® 40 AFL mm2 35 35 35 AFL = (d12 .8 x d1 de = d1 + 0.8 1. To optimise the fastening the hole diameter should not exceed Ø d = 0.0. for the same depth of thread engagement AFL. • The plastics can be modified in different ways. and so to a break in the part being clamped. since it gives a favourable distribution of edge stresses and so prevents the tube from shattering.4 x d1 Direct assembly in thermoplastics using Delta PT® screws d = 0. The results are then documented in the form of a «Technical Report». so that we can define and Min.9 2.5 3 3. The heat needed for low-stress formation of the thread in plastics is created by friction generated when driving in the screw.com T.6 10 15 21 28 44 have your screws manufactured to the required quality for automatic machines (delivery times ca.7 3.5 5 6 7 8 10 • Both electrically.and pneumaticallypowered screwdrivers can be used. The true screwing parameters can be established by Bossard. DELTACALC® cannot be purchased. using original components in their «Applications testing laboratory» The optimum tightening torque MA to be set on the screwdriver for the assembly process is determined based on customer-specific requirements.8 5.049 © 2005 by Bossard Home .com). fill it in and send it to Engineering at Bossard AG.9) Nominal size of Delta PT® 20 22 25 30 35 40 45 50 60 70 80 100 Nominal Ø (d1) in mm 2 2. Tensile fracture laod PT 10 version (Steel.Construction recommendations Direct assembly in thermoplastics using Delta PT® screws What should you consider during assembly? • Secure and cost-effective fastenings can only be produced with screwdrivers which have controlled torque and/or turning angle. strength analogous to 10. hardened and tempered.6 1.bossard. Based on VDI 2230. 1 driving in = tapping 2 bearing surface 3 tightening 4 over tightening Torque [Nm] Berechenbar mehr Leistung The preliminary design of screwed connections in thermoplastic can be simulated using the DELTACALC® calculation program. in order to allow for effects which have not yet been detected. then ask for a copy of the form for the input data ([email protected] 2. Time [sec] www. the difference between the driving torque (Me) and the stripping torque (Mü) must be as large as possible. it permits a design to be made related to the prestressing force. • The rotational speed should be between 300 and 800 rpm.5 4 4.2 6. Calculating the torque In order to achieve optimal safety during assembly. The automatic assembly of «standard stock screws» is not normally economically justifiable. 10 to 16 weeks). • If you want to assemble components using automatic screwing machines then get in touch with us as early as possible. • Trials using components should be made to check the calculated values and the repeatability of the screwing process. These possibilities range from dimensioning through load capacity and on to the working life of the connection. If you are working with connections which are under operational loadings. tensile fracutre load in kN 1.8 8. 3–0.80 x d1 0. specify a large head diameter (BN 20040).85 x d1 0.80 x d1 0.00 x d1 length of thread engagement te 2.GF 30 PMMA POM PP PP .GF 30 PE (soft) PE (hard) PET PET .80 x d1 0. • Avoid elongated holes in plastic parts.80 x d1 1.6 PA 4. hence causing greater joint relaxation in parts with narrow edge margins. The 90° head angle not only results in axial forces but also radial forces. This increases friction under the head.75 x d1 0.com T.80 x d1 0.72 x d1 0.80 x d1 2. The details shown here are based on laboratory testing.85 x d1 1.70 x d1 2. PT® screws have the necessary features to enable a secure joint in thermoplastics.00 x d1 1.85 x d1 0.82 x d1 0.85 x d1 1.95 x d1 2.70 x d1 1.6 PA 6.75 x d1 0.GF 30 PBT PBT .00 x d1 2. a counterbore (relief bore) is strongly recommended to minimize stress risers.0˚ Since these materials are more susceptible to stress cracking. • Do not use flat head screws.85 x d1 1.00 x d1 1.80 x d1 1.70 x d1 0.70 x d1 0.GF 30 PA 6 PA 6 .05 x d1 0.78 x d1 0.00 x d1 2.70 x d1 1. making a safer joint.70 x d1 1.20 x d11) 2.GF 30 PA 6. Some changes may be needed to fit your application.00 x d1 1.5–1.80 x d1 0.85 x d1 0.80 x d1 0.85 x d1 2.00 x d1 1.5 x d1 D Pressure relief hole Material ABS / PC blend ASA PA 4.70 x d1 2. Such a joint would be unsafe. as they would create a small bearing area.80 x d1 2.00 x d1 2.00 x d1 2.00 x d11) 2. • Shear forces should be absorbed by form-fitting components.73 x d1 0.00 x d1 2.00 x d1 1.20 x d1 2. Advantages of PT® screws • Low driving torque.050 © 2005 by Bossard Home .00 x d1 2.85 x d1 1.80 x d1 1.bossard.00 x d1 1. We recommend that users conduct application testing and joint analyses. Also.1–1.00 x d1 2. • Furnish the pilot hole entrance with a counterbore (avoids stress cracking) hole Ø d external Ø D 0.00 x d1 2.75 x d1 0.The PT® screw has been used successfully for years.77 x d1 2.00 x d1 1.6 . Also a larger head reduces the surface pressure which in turn minimizes joint relaxation and ultimately increases the residual clamp load. te = d s = L = 1.90 x d1 d1 = nominal thread diameter Ø Taper 0. requires the boss geometry to be adjusted to the different plastics. The preload would be unsafe. possibly causing the driving tor- Boss design for PT® screws An optimum boss design that will hold up in the application. 1) www.00 x d1 2.6 . high stripping torque • High assembly safety • Excellent vibration resistance • Low bursting tendency • No excessive joint relaxation therefore plastic components do not shift • Cost-effective fastener for direct fastening in thermoplastics Design guidelines • For fastening plastic parts.50 x d1 2.85 x d1 0.85 x d1 2.00 x d1 1.90 x d1 1.50 x d1 2.78 x d1 0.75 x d1 0.75 x d1 0.70 x d1 1.GF 30 PC PC .20 x d11) 2.00 x d1 2.80 x d1 1.2 x Le de = 1. it is highly recommended to carry out application testing.00 x d1 2.80 x d1 1.75 x d1 0.TV 20 PPO PS PVC (hard) SAN 30° Construction recommendations P Direct assembly in thermoplastics using Delta PT® screws que to be bigger than the under-head friction torque. 8 13 16 25 • If you want to assemble components using automatic screwing machines then get in touch with us as early as possible. • Trials made using components should be made to check the calculated values and the repeatability of the screwing process.9 improved tube shape Nominal Ø (d1) in mm 1. in order to compensate for the losses in resistance to stripping. Automatic assembly using screws from stock is not normally economically justifiable. using original components in their «Applications testing laboratory» The optimum tightening torque MA to be set on the screwdriver for the assembly process is determined based on customer-specific requirements. Min. The heat needed for low-stress formation of the thread in plastics is created by friction generated when driving in the screw.Construction recommendations Direct assembly in thermoplastics using Delta PT® screws Changes of shape Occur for the given shrink hole shape. shrink marks or extended injection cycles.051 © 2005 by Bossard Home . tensile fracture load in kN 1. strength analogous to 10. The results are then documented in the form of a «Technical Report». the form can be changed as follows: • Reduce external diameter D of the tube. (delivery times ca.and pneumaticallypowered screwdrivers can be used.com T. 10 to 16 weeks). hardened and tempered.bossard. The true screwing parameters can be established by Bossard.6 2 2.5 3 3. What should you consider during assembly? • Secure and cost-effective fastenings can only be produced with screwdrivers which have controlled torque and/or turning angle.5 4 5 6 7 8 10 • The rotational speed should lie between 300 and 800 rpm. D s 2/3 s s s shrink marks unsuitable tube shape Nominal size PT® K 18 K 20 K 22 K 25 K 30 K 35 K 40 K 50 K 60 K 70 K 80 K100 Tensile fracture load Steel.3 1.2 2. • Increase the diameter d of the hole • Increase tapping hole depth and so length of screw thread engagement.6 4. 1 driving in = tapping 2 bearing surface 3 tightening 4 over tightening Torque [Nm] Calculating the torque In order to achieve optimal safety during assembly.6 7 9.7 3. the difference between the driving torque (Me) and the stripping torque (Mü) must be as large as possible. • Both electrically. D Time [sec] www.1 1.8 2 2. L d Select tapping holes which are sufficiently deep so that under no circumstances can the assembled screws rest in the base of the hole. so that we can define and have your screws manufactured to the required quality for automatic machines. in order to allow for effects which have not yet been detected. Minimum total thickness of the sheet metals to be fastened The total thickness of the fastened parts shall be bigger than the thread pitch of the applied tapping screw. joints such as shown in figure 3 to 6 should be applied.Design guideline Sheet metal joints (use) according to DIN 7975 The informtion below represents general recommendations for the use of screws for sheet metal joints.052 © 2005 by Bossard Home . The different types are shown by way of example.com T. 4: Extruded core hole (thin sheet metal) Fig. or else. 2: Simple fastening with clearance hole Fig. 6: Fastening with spring nut www. a sufficient tightening torque can not be applied. Fig. Should this be the case. 3: Pierced core hole (thin sheet metal) Fig. 5: Pressed hole fastening joint Fig. because of the thread run out underneath the head. 1: Simple fastening (two core holes) Fig.bossard. 7 2.3 2.2 3.1 3.5 6. 300 up to 500 T.7 3.2 3.6 3.2 2.9 4.7 2.9 4.5 1.7 1.2 1.6 3.3 5.9 1.5 2.2 2.5 3.2 4.4 4.8 4.8 1.3 2.6 3.3 3.4 2.2 3.7 1.2 4.5 2.7 1.053 © 2005 by Bossard Home .3 ST 3. Prior tests must be carried for the utilisation of other screws or other sheet metal materials.6 4.8 5.2 5.45 1.7 4.2 3.8 1.0 5.1 3.6 3.2 3.5 1.1 3. The tightening torques are max.2 3.2 0.2 1.2 2.2 4.2 2.9 1. 300 up to 500 from 100 approx.1 3.0 3.4 2.8 Minimum breaking torque per DIN 267.0 3.9 2.7 3.6 3.9 2. type 12 Self-tapping screws Minimum breaking torque nominal Ø [mm] [Nm] ST 2.2 3.5 2.2 2.2 2.8 1.7 3.5 1.3 4.1–0.0 4.0 1.2 3.6 3.7 1.2 ST 4.3 1.9 4.1 4.9 1.4 2.3 5.0 5.2 2.7 1.2 4.8 2.7 5.7 1.8 ST 6.8 1.3 3.3 2.7 0.Design guideline Sheet metal joints Pilot hole diameter Self-tapping screws / sheet metal thickness / pilot hole diameters The following reference values are valid only for case hardened steel self-tapping screws as shown in Figure 2 on page Thread diameter Pitch P ST 2.7 1.bossard.3 3.2 2.0 3.9 5.9 4.3 3.9 3.2 2.2 5.3 mm larger.7 1.2 4.9 2.0 3.6 1.1 3.7 5.8 3.9 2.8 4.6 5.9 3.7 1.3 3.8 ST 5.7 2.4 3.9 1.6 3.0 3.9 4.4 3.4 4.3 3.8 1.7 4.2 4.5 ST 3. Diameter of the pilot hole for db thread dimensions ST 2.1 3.3 1.9 1.8 Material strength Rm [MPa] from 100 approx.2 3.2 3.7 2.4 1.0 2.8 5.5 5.0 3.9 1.4 2.2 3.0 5.6 3.2 4.6 ST 5.8 2.9 1.3 3.5 5.0 3.4 3.5 1.4 ST 4.4 3.9 2.0 3.2 4.9 ST 4.2 2.8 ST 2.7 1.7 2.0 4.5 3.1 3.3 2.5 4. 300 up to 500 from 100 approx.9 5.9 4.5 5.2 2.5 2.3 5.4 2.6 3.6 2.8 1.6 3.3 3.0 3.7 1.9 1.1 ST 3.7 4.8 2.5 ST 6.2 2.1 4.2 3.7 1.5 2.9 2.7 5.7 2.9 1.6 4.4 2.9 3.7 2.0 3.2 2.8 4.4 5.8 5.9 2.8 3.7 5. 300 up to 500 from 100 approx.3 2.4 5.8 1.8 3.7 1.4 3.2 2.2 ST 2.9 2.2 3.1 4.0 3.6 5.9 2.2 3.7 1.0 3.2 3.0 5.3 for a sheet metal thickness s [mm] 1.4 ST 4.0 3.0 2.0 4.9 3.2 3.7 2.3 2.com T.4 4.5 4.6 2.8 1.6 4.9 3.3 4.6 5. 300 up to 500 from 100 approx. 300 up to 500 from 100 approx.7 1.4 2.2 3.2 2. 50% of the minimum breaking torque.5 3.6 3.9 4.0 4.0 3.9 3.7 1.1 4.9 1.7 2.9 ST 3.7 2.9 4.7 4.1 1.8 2.7 2.4 4.2 2.7 2.4 3.9 5.2 3.0 4.5 10 14 www.7 5.4 3. The screws must be tightened in the direction the hole was punched.4 2.0 3. Punched pilot holes must be 0.3 3. 300 up to 500 from 100 approx.4 5.1 2.1 3.5 3.7 4.6 4.8 1.7 1. 300 up to 500 from 100 approx.6 3.8 4.7 0.4 3.7 1.1 5.3 0.2 2.1 4.3 3.8 4.3 2.5 5.5 3.0 4.6 3.3 3.4 3.3 3.8 3.8 2.8 3.8 4.2 to ST 6.052.4 5.2 4.7 2. polypropylene etc. Ensat® Type 302 Ensat® Type 305 Ensat® Type 307 / 308 Ensat® Type 337 / 338 Ensat® Type 309 Material Group Base material Recommended works standards Finishes / materials I Heat-treated aluminium with a tensile strength above 350 N/mm2 302 / 337 307 / 338 308 Steel hardened zinc yellow dichromate Cast iron in higher hardness range. Laminates) 302 302 / 337 307 / 338 308 Steel hardened zinc yellow dichromate Steel hardened zinc yellow dichromate 302 302 Brass Steel hardened zinc yellow dichromate Soft metals and aluminium with tensile strength up to180 N/mm2 302 Steel hardened zinc yellow dichromate or INOX A1 Laminates soft (press-board) 302 Steel hardened zinc yellow dichromate or Brass or INOX A1 Thermoplastics.Construction recommendations Selection crieria for self-tapping Ensat® inserts Grouping of materials. types and finishes.com T. brass. 302 Steel hardened zinc yellow dichromate Aluminium with a tensile strength up to 350 N/mm2 302 / 337 307 / 338 308 Steel hardened zinc yellow dichromate Cast iron 302 Thermoplastics Thermosetting plastics (Polyester plastics. bronze and other non-ferrous metals. Plexiglas) 302 / 337 307 / 338 308 Steel hardened zinc yellow dichromate Steel hardened zinc yellow dichromate or Brass Aluminium with a tensile strength up to 300 N/mm2 302 / 337 307 / 338 308 Steel hardened zinc yellow dichromate Soft cast iron Thermoplastics Thermosetting plastics (Nylon 66. Nylon 66 both reinforced.) Hardwoods 302 Steel hardened zinc yellow dichromate or Brass or INOX A1 V VI Hardwoods Softwoods and plywood Wood fiber materials 309 309 Brass Brass VII Thermoplastics 305 Brass II III IV Aluminium with a tensile strength up to 250 N/mm2 www.054 © 2005 by Bossard Home . (Polyethylene. Thermosetting plastics.bossard. 4–17.9 12.1 9/14 11/17 M10 13.5 d2 D d2 = Outside diameter (mm) of Ensat® insert DA = + 0. Thread M 2.3– 7.3 7.5–13. 6 6 6 8 8 10 12 14 15 18 22 24 22 27 30 Ensat® Type 309 Hard and brittle materials require a larger hole than soft and flexible ones.2 29.6 19. Material thickness: Length of Ensat® = shortest permissible Material thickness A 6 6 10 12 14 20 23 26 Ensat® Type 305 For material groups Ensat® Type I II III 307 / 308 Attainable percentage of overlapping threads 337 / 338 50%–60% 60%–70% 70%–80% Thread Hole diameter D [mm] M 3.3 to ≥ 0.055 © 2005 by Bossard Home .4–15.8–12. Recommended pilot hole diameters and material thickness / blind hole depths for threaded inserts Ensat® Recommendation for cast iron: S ≥ 0.5 5.9 5.6 3.2 17.3–10.com T.6 15. Material thickness A min.5–11.7– 7.8 14.2 4.Construction recommendations Selection crieria for self-tapping Ensat® inserts Blind hole depth: Minimum depth B 8 8 13 15 17 23 26 30 For material groups VII 6 8 10 14 7 9 11 15 Hole diameter D [mm] Thread M 3 M 4 M 5 M 6 Blind hole depth B min.6 17.8 8.1 15.8 28. Ensat® Type 302 The recommended hole diameter depends on the Ensat® external thread.1 10.9– 6.2–25 25 –24.5 9.6– 7.6–5.1–15 12/22 15/26 M14 17.6 11. Thread M 2.6 15.3– 4.8 24.6 29.1 7. the strength and the physical characteristics of the work-piece material.5 5.2 15.4 mm a = 1–1.3 8. Whenever necessary.2 19.2 7.3– 4.5 x the pitch of the external thread of the Ensat® www.7 4.2–17 17 –16. Recommendation for aluminum: S ≥ 0.2 13.5– 7.1 4.4 9.4–15.3– 5.6 10.bossard. Blind hole depth B min.6– 8.6 7.2– 6.7– 5.5 7.3– 8.6 d2 a The pilot hole can be drilled or formed during die-casting Countersinking the hole is usually not necessary.1– 4 4.6 5.2– 4.6 5.7– 7.6 4.6–12.1 6.8 16.6– 9.4–29.8 12.3–11.1 9. Material thickness A min. the most suitable hole diameter should be determined through application testing.2 25.3 13.1– 6 6/8 8/10 M 5 7.1 4.2–9 9 – 8.2–15 15 –14.2–15.8–15.1 5.8–16.4–19.2 11.9– 5.3 11.4 9 –9.4–13.4– 9. 8 8 8 10 10 13 15 17 18 22 26 28 27 32 36 For material groups V VI Attainable percentage of overlapping threads 85%–90% 90%–95% Hole diameter D [mm] 3.6– 7.1–6 6 – 5.2–13 13 –12.7– 6.1 8.5 M 2.5 4.6 Blind hole depth B min.2 15.4– 5.2–11 11 –10.1 6.2–4.4 5.8–12.1– 4 4.8–24.4– 9.6 7.5 7.7 6 –6.6 25.2 Minimum wall thickness: The wall thickness is dependant upon the hardness and / or strength of the workpiece material.7– 5.3 8/12 10/15 M 8 11.1 6.1 6.2 8.1 17.2 4.6 5.2 13.2 5.5 M 3 M 4 M 5 M 6 M 8 M10 M12 Blind hole depth B min.8 7.5 M 4 M 5 M 6a M 6 M 8 M10 M12 M14 M16 M20 M24 For material groups I II III IV Attainable percentage of overlapping threads 30%–40% 40%–50% 50%–60% 60%–70% Hole diameter D [mm] 4.5–7.6–4.3 to ≥ 0.1 10/18 13/22 M12 15.2 4.7 4.4 15.8–18.7 7.2–17.2–29 29 –28.2–13.8– 3. Material thickness A min.8 18.8–28.2 4.8–14.6– 3.2 11.6 M 3 M 3.2– 7.1– 9.6– 5.4 Material thickness A min.2 9.4–11. however it would facilitate installation and possibly prevent damage to the workpiece surface.2–11.6 12.5– 9.2 to 0.5 5/8 7/10 M 4 6.8–10.2–19 19 –18.8– 8.3–7.6– 4.6–15.3–13.5 5.1–17 14/24 17/28 a 60° D DA 4.5–8.8 10.2– 8.9– 7.6 13.4–25. It also would enable the insert to be flush with the work-piece.3 6.4 7/10 9/13 M 6 9.4–17.1 4.7 6.2 17.2– 6.2– 5.5– 5.3– 4.5 8.8– 4. – The general dimensions are given in the product information in the catalogue. Cross recess Z (Pozidriv) according to ISO 4757 – The Pozidriv cross recessed head is used principally in Europe. this system is characerised by a lower risk of deterioration and a lower pressure force requirement. Hexalobular socket – The notion of a drive with hexalobular sockets are a decisive step in developing drives better adapted to manual and automated assembly. – The general dimensions are given in the product information in the cataloguee. the end of the screwdriver having trapezoid webs. Hexagon socket – Screws with hexagon socket head have proved their worth in the machine and apparatus construction fields. procurement and assembly.bossard. – It is very important today to take into account the most frequently used drives and their possibilities in design. – Has a conventional cruciform recess with all walls inclined. – The general dimensions are given in the product information in the catalogue.com T. are perpendicular.056 © 2005 by Bossard Home . The other walls are inclined. The typical «cam out» slipping of the tool has hence been eliminated and the force transmission improved. logistics. www. The Pozidriv screwdriver has rectangular webs at its extremity. This can improve assembly if the recess production is reliable. Cross recess H (Phillips) according to ISO 4757 – The Phillips cross recessed head is the world’s most widely used system. – The four «tightening walls» of the cruciforme recess in contact with the screwdriver when tightening.Construction recommendations Internal drives for screws – Technical progress and economic factors have resulted in the increasing replacement of slotted head screws by other internaldrive systems. – Compared to drives like cross recesses and conventional hexagon sockets. – The general dimensions are given in the product information in the catalogue. This drive is becoming increasingly popular throughout the world. – The width across flats of hexagon socket head screws is smaller than the WAF of hexagon head screws. permitting more economic design with smaller sizes. – The cross section of the Torx plus® drive is larger compared to the hexa-lobular system. The high property class 10. The force applied is that actually used for tightening the screw. – The good force transmission enables low penetration depths. www. The geometries of the hexalobular socket and the Torx plus® therefore extend the service life of the screwdriver bits by up to 100%. Can accept the tightening torques for all property classes. – The Torx plus® system is compatible with the tools provided for the (Torx®) hexalobular system.9 of these screws permitting increased strength of the hexagon socket can be reduced toproperty class 8. however able to cope with high stresses with respect to permissible surface pressure. No problem assembling round head screws according to ISO 7380 and recessed flat head screws DIN 7991. Therefore the torsional strength of the driving tool is increased. No deterioration of the internal drive. the specific geometric benefits of Torx plus® can only optimise assembly when using the Torx plus® screwdriver bits (tool). Very low assembly tool wear. High rationalisation potential for the assembly technique. as the drive is suitable for all types of screw Economic head from the aspect of size.com T. corresponding to cheese head screws DIN 84 and DIN 7984. However.bossard. form and material. Technical advantages of hexalobular socket and Torx plus® drives and their economic benefit No need for pressure force as is necessary when using cross recessed drives. The hexalobular socket and the Torx plus® systems have benefits due to their design parameters 60° Force transmission angle of 60° with hexagon socket drives 15° Force transmission angle of 15° with hexalobular socket drives 0° Force transmission angle of 0° with Torx plus® drives – The effective transmission angle of the hexalobular socket is 15° and that of the Torx plus® is 0°.8. – The general dimensions are given in the product designations in the catalogue. hence reliable unscrewing.Construction recommendations Internal drives for screws Torx plus® – The Torx plus® drive is defined by ellipses and represents an improvement over the original hexalobular system which is defined by a series of radii.057 © 2005 by Bossard Home . This produces the necessary clearance and a defined range for permissible plating thicknesses: a plated screw thread must never exceed the nominal dimensions. nut thread dimensions.058 © 2005 by Bossard Home . TD1 2 TD2 2 El 2 bolt thread nut thread Tolerance fields for commercial screws and nuts according to ISO 965 major diameter min. 6H Mutter 6H es 2 pitch diameter min. D major diameter D nominal size of thread Nut 60° Bolt P pitch Nut Bolt Clearance fit on metric ISO threads according to ISO 965 The ISO 965 thread standard recommends tolerance fields which give the desired clearance. major diameter min. Terms and fitting systems are difficult to understand.027). minor diameter min. pitch and minor diameter. The thread dimensions and profile accuracy are crucial for determining: pitch diameter max. phosphated or for standard electroplatings bright (with large clearance) or for very thick electroplatings 6g-ring ganges for plain screw threads 6h-ring ganges for plated screws Td 2 major diameter max. the following illustrations explain dimensions and tolerances. Screw and nut threads have different tolerance zone positions: screw thread dimensions are situated at the nominal dimensionand below. To assist.Metric ISO threads D1 minor diameter D2 pitch diameter The dimension system for threads is based on the nominal dimensions for thread. Nut major diameter max. minor diameter max. General Tolerance fields of screw and nut threads www. while a plated nut thread must never fall below them (see T. • whether the parts to be joined can be screwed together on assembly without difficulty or the need for reworking. • whether the thread can transmit the forces for which the components were dimensioned.bossard. pitch diameter min. at the nominal dimensionand above. the following tolerance fields are standard! 6e 6g 6G Clearance before application of O protective coats 6e Larger number means greater tolerance. d major diameter Basic concept and nominal dimensions according to ISO 724 d2 pitch diameter • whether a coating can still be applied to the screw thread. Oberflächenzustand bright. G –H–h g f e Ø major Ø pitch 6G 4 5 6 7 8 Ø major Ø pitch Bolzen 6g Bolt Tolerance quality Diameter-dependent tolerances for different tolerance qualities can be found in ISO 965. For threads ≥ M1.com T. pitch diameter max.4. Td2 2 Tolerance zone position Pitch-dependent dimensions for different tolerance zone positions can be found in ISO 965. • Tolerances are very small in screw manufacturing. 376 10.701 13.038 1.4 1.8 4.655 3.4* M 1.682 15.462 30.35 0.075 0.5 1.212 6.874 3.Metric ISO threads Limits for metric (standard) coarse threads according to ISO 965 Screws.554 1.670 451) 481) 1) Pitch P 0.940 Pitch diameter d2 (mm) min.838 1.219 0.7 2 2.940 38.599 3.663 14.25 0.933 1.952 29.663 16.675 3.4* M 1.829 12.7 2 2.679 12. 0.013 2.503 14.775 3.462 33.210 14.727 33.5 4.8 4. 0.500 0.324 7.402 421) Minor diameter D1 (mm) max.438 0.491 1.3 0.523 4.221 1.270 min.133 1.6 0.354 3. 0.674 30.250 0.8 1 1.654 2.835 13.153 6. 0.2* M 1.5 9 9 12 15 18 24 24 30 30 30 36 36 45 45 53 53 Pitch diameter D2 (mm) max.051 27.794 6.886 2.838 1.75 2 2 2.375 0.744 21.8 M 2 M 2.972 9.050 0.985 1.917 5.088 0.316 28.438 0.149 1.8 0.6 3 3.325 1.952 26.117 2.5 3.313 0.7 2 2. 0.6 0.334 5.744 17.729 0.968 11.794 7.164 18.8 1 1 1.5 M 4 M 5 M 6 M 7 M 8 M10 M12 M14 M16 M18 M20 M22 M24 M27 M30 M33 M36 M39 Length of thread engagement from 0. tolerance 6H (*5H) Thread M 1* M 1.142 1.313 0.4 0.929 1.623 19.985 1.373 1. 1.242 4.894 1.962 17.5 5 6 7.5 M 3 M 3.200 1.com T.6 M 1.026 10.679 2.044 0.138 2.004 3.976 5.350 6.521 1.5 3 3 4 5 6 8 8 10 10 10 12 12 15 15 18 18 to 1.577 26.785 0.8 2 2.682 17.522 32.465 38.732 11.994 10.007 33.980 3.250 0.6 0.500 7.863 12.605 5.6 0.400 1.125 0.752 23. 0.160 8.380 2.206 11.835 15.744 19.974 6.7 1.727 30.7 0.110 3. 0.740 2.771 32.771 29.458 1.701 16.376 20.205 1.5 2.663 4.031 0.459 2.913 14.8 0.038 1.205 1.912 8.958 21.375 0.803 24.252 24.5 2.35 0.188 0.376 18.153 6.bossard.354 1.500 Selection series for coarse threads according to ISO 262 Thread nominal diameter Reihe 1 Reihe 2 1.702 min.7 1.702 36.422 4.5 M 3 M 3.208 2.567 2.6 2.600 20.6 M 1.480 5.830 2.862 10.803 27.966 13.361 5.6 0.658 1.402 36.958 19.7 0.947 32.334 20.059 © 2005 by Bossard Home .063 12.623 21.500 6.913 16.252 26.25 1.465 max.421 1.5 M 4 M 5 M 6 M 7 M 8 M10 M12 M14 M16 M18 M20 M22 M24 M27 M30 M33 M36 M39 39 Length oft thread engagement from 0.696 1.441 12.781 1.917 6.8 M 2 M 2.958 23.376 22.003 25.125 0.211 31.545 4.164 21.760 9.313 0.3 1.647 8.6 1.456 5.5 1.974 7.5 0.118 26.5 3 3 4 5 6 8 8 10 10 10 12 12 15 15 18 18 to 1.342 min.981 2.503 16.106 11.211 29.623 23.600 22.479 3.094 1.3 1.5 3 3.674 33.5 9 9 12 15 18 24 24 30 30 30 36 36 45 45 53 53 Major diameter d (mm) max.210 15.2* M 1.042 8.5 5 6 7.826 5.573 1.600 18.580 3.947 35.010 3.5 5 Not contained in ISO 262–1973 www.044 0.056 0.051 25.038 0.212 7.100 0.294 20.089 3.003 27.291 1.850 3.063 0.25 0.324 6.270 35.7 2 2.45 0.316 25.222 3.480 2.676 10.265 1.433 4.5 1. tolerance 6g (*6h) Thread M 1* M 1.577 29.031 0.334 18.188 2.118 Thread root radius (mm) min.670 34.962 15.701 14.721 2.2 1.838 4.156 0.164 20.321 1.348 9.188 9.581 1.5 4 4 4.7 0.294 19. 0.334 22.5 3 3 3.752 26.6 3 3.000 1.8 1 1.785 0.294 17.342 26.5 4 5 6 7 8 10 12 14 16 18 20 22 24 27 30 33 36 Nuts.6 2.007 31.496 1.978 4.350 7.134 4.075 1.522 35.303 2. 962 23. for all other tolerances.854 12.003 min.160 11.316 min.835 32. but with the factor 2.6 8 8.732 13.794 9.503 22.6 8 5.762 17.483 28.663 22.962 32.835 30.350 9.913 19.962 21.375 Selection series for fine threads according to ISO 262 Nominal thread diameter series 1 series 2 8 10 12 14 16 18 20 22 24 27 30 33 36 39 Pitch P 1 1.994 12.732 15.6 8 5.5 8.994 16.701 19.5 M20x2 M22x1.760 11. For moredetailed specifications.6 5.25 M12x1.493 31.216 15.324 9. 7. 0.854 16.912 10.5 M14x1.500 9.5 M22x2 M24x2 M27x2 M30x2 M33x2 M36x3 M39x3 Length of thread engagement from 3 3 4 4. 6.803 Thread root radius (mm) min.676 20.676 16.663 25.210 31.188 0.676 18.5 M20x2 M22x1.210 18.376 19.212 9.348 11.854 18.210 20.376 12.216 18.6 5.5 8.925 25.994 14.25 1.376 15.962 35.794 9.834 27.376 16.493 33.577 38.663 34.968 17.752 Permissible tolerances for plastic fasteners Dimension major Ø minor Ø pitch Ø pitch for screw threads e8 2 x g8 for nut threads 2 x G7 H7 2 x g8 ± 5% Dimensions of the head.5 8.026 13. Acceptance according to VDI 2544.5 1.376 17.188 0.210 28. 7.968 17.156 0.028 10.925 31.5 M18x1.375 0.5 1.026 15.5 8.682 29.051 Minor diameter D1 (mm) max.188 0.216 13. 7.5 12 12 Pitch diameter D2 (mm) to 9 9 12 13 16 16 16 16 24 16 24 16 24 25 25 25 25 36 36 max.647 10.854 20.5 8. 7.160 10.350 9.25 M12x1.051 37.972 11.210 25.500 9.5 12 12 Major diameter d (mm) to 9 9 12 13 16 16 16 16 24 16 24 16 24 25 25 25 25 36 36 max.324 9.252 min.6 8 8.5 M14x1.5 2 2 2 2 3 3 11) 1.701 22.5 5.188 0.994 16.994 18.676 12.212 9. refer to ISO 4759.5 M22x2 M24x2 M27x2 M30x2 M33x2 M36x3 M39x3 Length of thread engagement from 3 3 4 4.682 32.682 26.042 11.732 19. screw length and thread approximate according to DIN. 7.188 0.968 19.974 9.994 20.835 24.972 11.952 Pitch diameter d2 (mm) min.974 9.6 5.503 20.188 0.156 0.962 29.25 1.803 36.854 14.060 © 2005 by Bossard Home .6 8 5.663 20. These technical recommendations are of a general nature.5 M18x2 M20x1.503 18.925 34.156 0.835 18.952 19.153 9.701 28.216 17.701 25. please refer to VDI 2544.913 22.156 0. 7.188 0.676 16.682 35.003 37.493 25.5 1.682 19.5 M16x1.917 8.026 16.5 M16x1.968 13.216 16.701 31.663 18.854 16.188 0. tolerance 6H Thread M 8x1 M10x1 M10x1.701 34.917 8.752 35.701 21.682 23.6 8 5. part 1.835 20.912 10.250 0. www.952 38.676 14.026 20.250 0.6 5.252 36.663 31.188 11.682 21.250 0.6 5.bossard.968 15.913 21.5 8.com T.026 13.732 17.925 28.316 37.188 11.153 8.732 21.125 0.5 5.51) 21) 21) 21) Not contained in ISO 262–1973 1) Nuts.962 26.216 20.210 33.835 21.25 M12x1.026 17. 7.250 0.577 max. The tolerances must be observed 24 hours after fabrication.210 22.6 5.5 1.368 11.376 14.760 11.5 M18x2 M20x1.25 M12x1.663 28. tolerance 6g Thread M 8x1 M10x1 M10x1.5 M18x1.968 21.647 10.Metric ISO thread Limits for metric fine threads according to ISO 965 Screws. 019 0 +0.04 0 -0.089 0 -0.029 0 -0.18 0 +0.04 0 H7 +0.3 0.070 -0.068 -0.23 0 -0.075 0.006 0 -0.57 0.89 0 -0.137 +0.39 0 +0.043 +0.185 0 +0.5 ±0.02 0.48 0 +0.9 0 -1.1 0.86 +0.023 www.21 0.022 0 +0. range up to over up to over up to over up to over up to over up to over up to over up to over up to over up to over up to over up to over up to 3 3 6 6 10 10 18 18 30 30 50 50 80 80 120 120 180 180 250 250 315 315 400 400 500 Nominal dim.015 +0.009 0 +0.89 1.5 0 -4 0 -4.052 +0.18 0 -0.35 ±0.5 +0.035 0 +0.046 0 +0.151 +0.36 0 +0.048 0 -0.18 ±0.063 +0.2 0 -1.075 0 -0.29 0 +0.62 0 -0.008 +0.165 -0.043 -0.3 0 -1.36 0 -0.45 ±0.115 0 -0.057 +0.6 ±0.12 0 -0.074 0 -0.11 0 +0.018 0 +0.45 ±2.025 -0.062 0 -0.076 +0.25 0.058 0 -0.029 0 +0.4 +0.03 0 +0.52 0 +0.052 0 +0.87 0 -1 0 -1.14 0 -0.02 -0.46 0 -0.7 1.04 0 +0.47 +0.145 0.12 0 -0.033 0 +0.018 0 -0.035 +0.002 +0.059 -0.3 js17 ±0.13 0 +0.3 3.3 0 -0.1 0 -0.5 +0.48 0.57 0 +0.52 0.01 +0.202 -0.16 0 -0.05 ±0.15 ±0.36 0 -0.009 0 -0.25 0 -0.52 0 -0.4 0 H12 +0.4 0 -0.14 0 +0.3 0 -0.036 0 +0.62 0 +0.046 +0.036 +0.022 0 -0.46 0.004 +0.4 2.03 +0.9 ±0.031 -0.057 0 +0.013 +0.011 0 -0.013 0 -0.3 0 +0.05 ±1.089 0 +0.22 0.04 0 -0.4 h12 0 -0.035 0 -0.63 h13 0 -0.575 ±0.1 0.72 0 +0.21 0 -0.36 0.2 0 +1.054 0 -0.25 ±2 H15 +0.052 0 -0.009 +0.2 js16 ±0.6 2.6 0 +1.04 0.25 ±1.2 +0.025 0 -0.165 +0.8 0 -2.3 0 -2.97 0 H14 +0.17 0.09 0 -0.43 0 +0.6 1 +0.bossard.03 -0.18 0 +0.32 0.063 0 H8 +0.75 ±0.21 0 +0.043 0 +0.84 1.016 -0.63 0 +0.084 0 -0.046 0 -0.011 0 +0.052 0 -0.068 H6 +0.04 -0.014 0 +0.33 0 +0.5 0 -1.1 ±1.775 ±1.7 +0.15 +0.043 0 -0.1 0 -1.16 0.1 0 -2.25 0 +0.81 0 +0.155 h10 0 -0.2 1.74 0 -0.007 +0.019 0 -0.013 +0.062 0 +0.54 0 +0.925 ±1.1 0 +2.25 0 -0.12 0.48 0 -0.2 0 -3.74 0 +0.185 0 -0.021 +0.7 0 -6.6 2.01 0 -0.19 0 +0.2 0 -5.18 0.4 0.215 ±0.4 0.8 ±0.012 0 +0.4 0 +1.125 ±0.13 0.5 ±1.12 0.62 1 1.29 0 -0.15 0.71 +0.06 0 -0.3 0 -1.008 0 -0.35 0.58 0.084 0 +0.062 -0.4 0 +0.3 0 +0.046 0 +0.42 ±0.6 ±0.6 0 -1.087 0 +0.21 0 -0.013 0 +0.74 1.43 0 -0.123 -0.065 0.043 +0.021 0 -0.06 0.25 0 +0.58 0 +0.1 0 +0. range up to over up to over up to over up to over up to over up to over up to over up to over up to over up to over up to over up to over up to 3 3 6 6 10 10 18 18 30 30 50 50 80 80 120 120 180 180 250 250 315 315 400 400 500 Standard tolerances [mm] Tolerance fields for internal dimensions [mm] IT11 IT12 IT13 IT14 IT15 IT16 IT17 D12 0.7 0 +0.13 0 -0.27 0 +0.1 +0.1 3.081 0 -0.63 0 -0.015 0 +0.053 +0.25 0 H11 +0.02 +0.036 0 +0.97 h14 0 -0.9 4.012 +0.55 h15 0 -0.Tolerances / Tables / Standards Basic tolerances and tolerance fields Extract from ISO 286-2 Nominal dim.015 0 -0.33 0 -0.3 2.78 +0.01 -0.33 0.05 +0.545 +0.052 0 +0.15 0 +0.018 +0.3 0.84 0 -1 0 -1.033 0 -0.22 0 +0.021 0 +0.008 +0.04 0 +0.097 h9 0 -0.52 0 -0.7 ±1.4 0 -0.016 0 +0.03 0 +0.12 0 +0.25 0 +0.37 ±0.22 0.097 0 H9 +0.23 0 +0.3 +0.15 ±0.36 0 +0.23 F8 +0.11 0 -0.006 0 +0.02 +0.25 0.85 ±2 ±3.19 +0.3 ±0.35 0 +0.15 0 -1.05 0.11 0.122 +0.18 0.4 0.43 0.015 +0.46 0 +0.21 0.75 1.01 0 +0.12 +0.03 0 -0.05 -0.016 +0.025 0 +0.039 0 +0.115 0 +0.89 0 +0.31 ±0.6 +0.036 0 -0.4 0 +0.087 0 -0.004 +0.061 © 2005 by Bossard Home .12 0 +0.104 -0.022 0 +0.017 +0.16 0 -0.55 0 js14 js15 ±0.025 +0.75 ±0.056 +0.26 ±0.2 +0.1 0 -2.6 0 -4 h17 0 -1.29 ±0.14 0 +0.4 0 -1.87 1.95 ±1.84 0 +1 0 +1.046 0 -0.7 0 -0.3 0 +2.22 0 -0.6 5.36 0.6 0 -1.049 -0.27 0.054 0 +0.04 h7 0 -0.375 ±0.011 +0.039 0 -0.2 3.46 0 -0.075 0 +0.04 +0.9 1.87 0 +1 0 +1.46 0 +0.21 0 +0.1 0 +0.016 0 -0.5 0 -3 0 -3.07 0 -0.7 ±1.013 -0.97 1.5 +0.72 1.074 0 +0.072 0 +0.143 -0.55 ±0.435 ±0.14 0 -0.8 ±2.32 0 -0.24 ±0.006 +0.15 0 +1.025 0 -0.155 0 H10 +0.106 +0.63 1 1.85 0 +2.1 0 -0.032 0 +0.5 0 -2.09 0 +0.056 -0.com T.07 0 +0.25 0 -0.14 0 -0.03 0.025 0 +0.85 0 -2.5 ±0.6 ±2.09 0.8 ±0.6 0 -5.03 +0.048 0 +0.39 0 -0.06 0 +0.13 0 -0.72 0 -0.25 0.19 0.223 h6 0 -0.9 0 -2.014 0 -0.58 0 -0.25 m6 +0.1 0 +0.036 -0.1 0 -0.057 0 -0.03 0 -0.036 0 -0.27 0 -0.81 0 -0.008 0 +0.9 3 +0.46 0.54 0 -0.15 0 -0.15 ±1.087 -0.6 ±0.185 -0.15 1.5 4 +0.14 0.65 ±1.25 h11 0 -0.4 0 -1.23 +0.08 0.018 0 +0.081 0 +0.5 4 6.09 +0.63 0.2 5.18 0 -0.5 0 Tolerance fields for external dimensions [mm] f9 -0.012 0 -0.9 0 -3.5 h16 0 -0.02 +0.33 +0.025 0 +0.022 0 -0.63 +0.57 0 -0.63 0 H13 +0.063 0 -0.018 0 -0.81 1.52 0 +0.062 +0.6 0 -0.3 2.032 0 -0.025 0 -0.65 ±1.025 +0.19 0 -0.006 -0.2 0 -2.14 0 +0.75 0 -0.4 0 +1.275 +0.52 0.32 0 +0.4 2.13 0 +0.063 h8 0 -0.2 0 -1.1 1.19 0.021 +0.54 0.16 0 +0.85 2.22 0 -0.006 +0.8 +0.058 0 +0.063 0 +0.35 0 -0.027 0 +0.39 0.3 ±0.035 +0.22 0 +0.55 2.16 0 +0.027 0 -0.29 0.028 +0.3 0 +1.072 0 -0. 02 · 10–5 10.062 © 2005 by Bossard Home .102 10–3 1 1. heat flow Electrical charge.81 10–5 p 102 1 1000 1.Tolerances / Tables / Standards SI units system SI is the modern system of units for measurement.02 · 10–7 0.81 · 106 N/mm2 10–6 1 9. Basic units of the SI system Quantity Name Symbol Length Mass Time Electric current Termodynamic temperature Luminous intensity Amount of substance Plan angle Solid angle meter kilogram second ampere kelvin candela mole radian steradian m kg s A K dc mol rad sr 2. Supplementary units. quantity of electricity Plectrical potential. SI is built of: Base units. potential. technology and trade and is applied in the same way world wide. Additional units.102 10–2 1 Conversion table for units of mechanical stress 1 Pa = 1 N/m2 1 N/mm2 = 1 Mpa 1 kp/cm2 = 1 at 1 kp/mm2 Pa 1 106 9. energy flow.81 www.02 · 10–3 kp 0.bossard. heat) Power. SI is used in all areas of science. Derived SI units Quantity Name Symbol Defining equation Frequency Force Pressure and mechanical stress Work (energy. It is used in all areas of international standards and is commonly referred to as the metric system.2 1 100 kp/mm2 1. accepted and used world wide.81 · 105 1 kp/cm2 1.com T.81 · 10–3 9. Prefixes. The figures given in the conversion tables are rounded up to 3 or 4 digits.81 · 10–2 9. diffenrence voltage Electric capacitance Impedance Electrical conductivity Magnetic flux Magnetic flux density Industance Luminous flux Illumination hertz newton pascal joule watt coulomb volt farad ohm siemens weber tesla henry lumen lux Hz N Pa J W C V F Ω S Wb T H lm lx 1 Hz 1N 1 Pa 1J 1W 1C 1V 1F 1Ω 1S 1 WB 1T 1H 1 lm 1 lx = 1 s–1 = 1/s = 1 kg · m/s2 = 1 N/m2 =1N·m=1W·s = 1 N · m/s = J/s =1A·s = 1 W/A = 1 A · s/V = 1 V/A = 1 Ω–1 = 1 A/V =1V·s = 1 Wb/m2 = 1 Wb/A = 1 V · s/A = 1 cd · sr = 1 lm/m5 Conversion tables Conversion table for units of force 1 Newton = 1 N 1 pond = 1 p 1 Kilopond = 1 kp 1 dyn N 1 9.02 · 10–6 dyn 105 981 9.81 · 104 9. 1. com T.1 N/mm2 1 kp/m2 1 at = 1 kp/cm2 1 Torr = 1/760 atm Pa 1 105 9.81 · 104 133 bar 10–5 1 9.187 · 103 J/kg · K 1 Oe = 79.1 MPa = 0.187 · 103 J/K 1 kcal/m · h · °C = 1.063 © 2005 by Bossard Home . energy and heat 1J=1N·m=1W·s 1 kJ 1 kWh 1 kcal 1 kpm J 1 1000 3.000 000 001 g / kg (10–9) 1 picogram per kilogram 0.81 9.163 W/K · m 1 kcal/kg · °C = 4.6 · 103 1 8.860 860 3.81 1 W = 1 N · m/s = 1 J/s 1 kW 1 kcal/s 1 kcal/h 1 kpm/s kW 10–3 1 4.78 · 10–7 2.16 9.19 · 103 9.81 · 10–5 0.81 · 10–3 kWh 2.Tolerances / Tables / Standards Conversion tables Conversion table for units of work.019 cd 1 sb = 104 cd/m2 1 rem = 0.02 · 104 1 104 13.81 · 10–3 Conversion table for units of pessure for gases.81 kJ 10–3 1 3. candle Stilb Rem Röntgen Symbol Å mm Hg erg PS P St Oe G M lK sb rem R New unit meter pascal joule watt pascal second cm2 / s J / cm2 J/K W/K·m J / kg · K ampere / meter tesla weber candela cd / m2 J / kg C / kg Symbol m Pa J W Pa · s A/m T Wb cd Defining equation 1 Å = 10–10m 1 mm Hg = 133.02 10–4 1 1.58 · 10–4 C/kg Conversions of part volumes 1 ppm (part per million) is 1 part out of 1 million parts 1 milligram per kilogramm 0. US English for milliard) litres 1 ppt (part per trillion) is 1 part out of 1 billion parts (t = trillion US English for billion) 2.6 at 1.981 1.36 · 10–2 736 1 Conversion of othe units into SI units Value Length Pressure Energy Power Dynamic viscosity Kineamtic viscosity Impact value Heat capacity Heat conductivity Specific heat Magnetic field strength Magnetic flux density Magnetic flux Luminous intensity Luminace Absorbed dose Ion dose Previous unit Ångström mm mercury Erg horsepower Poise Stokes kpm / cm2 kcal / °C kcal / m.78 · 10–4 1 1.67 · 105 427 1 kcal/s 2.239 1 2.119 1 Conversion table for units of power and heat flow W 1 1000 4.6 · 103 4.h °C kcal / kg °C Oersted Gauss Maxwell internat.102 102 427 0.5 · 10–3 750 7.5 W 1 P = 0.34 kpm/s 0.02 · 10–5 1.bossard.3 Pa 1 erg = 10–7 J 1 PS = 735.239 860 1 2.7 trillion litres www.16 · 10–3 2.000 000 000 001 g / kg (10–12) 2700 litres Example: one lump of sugar dissolved in: 1 ppb (part per billion) is 1 part out of 1 milliard parts 2.1 Pa · s / 1c P = 1 m Pa · s 1 St = 1 cm2/s = 10–4 m2/s 1 kpm/cm2 = 9.36 · 10–3 Torr 7.102 1.34 · 10–3 kcal/h 0.7 million (b = billion. vapours and liquides 1 Pa = 1 N/m2 1 bar = 0.6 · 10–3 9.001 g / kg (10–3) 1 mikrogram per kilogram 0.102 102 3.39 · 10–4 0.19 1.19 9.9 · 103 1.7 billion litres 1 ppq (part per quadrillion) is 1 part out of 1 billiard parts (q = quadrillion US English for billiard) 2.72 · 10–6 kcal 2.78 · 10–4 2.33 · 10–3 kp/m2 0.39 · 10–4 0.6 A/m 1 G = 10–4 T 1 M = 10–8 Wb 1 lK = 1.01 J/kg 1 R = 2.34 · 10–3 kpm 0.6 · 106 4.000 001 g / kg (10–6) 1 nanogram per kilogram 0.087 J/cm2 1 kcal/°C = 4. ) (kg) (dz.74 Temperature °C = °F (exact) Conversion from Celsius into Fahrenheit: Multiply by 1.35 0.85 0.inches sq.1 70 65.) Measures of area metric – USA 1 mm2 1 cm2 1 m2 1 m2 1 km2 0.00155 0.2 –17.) (qt.1 – 6.4400 0.8 °C 100 95 90 85 80 75 70 65 60 55 50 45 40 0.957 4.8 80 76.836 2. divide result by 1.in.7640 1.feet sq.113 1.) (sq.4536 907.200 9.m.8 82.) (sq.yard 1 sq.) (gal.0567 0.3 °F 104 100 90 86 80 70 68 60 50 40 – 32 30 20 14 10 0 °C 40 37.) (sq.4 – 0 – 1. t USA – metric 1 psi 1 in lb 1 ft lb psi in lb in lb °F 212 200 194 190 180 176 170 160 158 150 140 130 122 120 110 °C 100 93.7989 28. Conversion from Fahrenheit into Celsius: Subract 32.609 mm cm mm cm m cm m m km (sq.00 0.) (pt.1 20 15 10 4.7 –10 –12.9 43.) (lb.14 8.) USA – metric 1 sq.fl.039337 0.) (in.46 2204.800 30.miles Measures of capacity metric – USA 1 milliliter (ml) 1 centiliter (cl) 1 deziliter (dl) 1 liter (l) 1 liter (l) 1 hectoliter (hl) 0.inch 1 sq.417 Weights metric – USA 1 gram 1 kilogram 1 quintal 1 tonne 1 tonne (gr.35 °F 212 203 194 182 176 167 158 149 140 131 122 113 104 N/mm2 Nm Nm70 °C 35 30 25 20 15 10 5 – 0 – 5 –10 –15 –17. add 32 to result.38614 sq.102 Various metric – USA 1 N/mm2 = 1 MPa = 10 bar 1 Nm 1 Nm 145.8 °F 95 86 77 68 59 50 41 – 32 23 14 5 0 www.) (lb.fl.540 304.8.4 50 48.3048 91.) (lb.0929 0.1550 10.9144 1609.) (ft.com T.3700 3.) USA – metric 1 fluid ounce 1 pint 1 pint 1 quart 1 gallon 1 barrel (bl) 1 barrel 2.196 0.0936 0.2 30 26.mile 645.inches sq.39370 39.237 1.foot 1 sq.16 6.7 71.732 0.2808 1.8.00689 0.62137 inches inches inches feet yards miles (in.) (in.432 2.) (yd.400 2.inch 1 sq.7853 119.) USA – metric 1 grain 1 ounce 1 pound 1 short 1 short 1 short 64.sh.192 cl dl l l l l hl grains pounds pounds pounds short tons (gr.foot 1 sq.5889 mm2 cm2 cm2 m2 m2 km2 fluid drachms fluid ounces pints quarts gallons gallons (dr.) (tn.0528 1.26 26.9072 mg g kg kg dz.2046 220.) (gal.) (sq.3 90 87.4516 929.064 © 2005 by Bossard Home .480 0.bossard.yard sq.in.Tolerances / Tables / Standards Conversion tables metric – USA USA – metric Measures of length metric – USA 1 millimeter (mm) 1 centimeter (cm) 1 meter (m) 1 meter (m) 1 meter (m) 1 kilometer (km) 0.072 0.4732 0.35 1.) (m.27 0.6 60 54.6 1. USA – metric 1 inch 1 inch 1 foot 1 foot 1 foot 1 yard 1 yard 1 mile 1 mile 25.338 0.7 21.8 32.yd.) (oz.) (t) (t) 15.9463 3.ft. 4 62.5 63.1 84.2 82.2 75 78.Tolerances / Tables / Standards Hardness comparison table according to DIN 50150 The comparison table below is valid only for carbon steels.7 48.4 67 67.4 49.8 81.5 79.2 95 99.4 84.8 80 80.6 62 62.8 40.5 92.4 67 67.6 37.3 73. Furthermore the Brinell hardness values in brackets are only valid if the test was carried out with a hard metal ball.5 36.7 60.1 68.3 85.1 49.8 59.1 99.7 69.5 29.6 83 83.6 54.4 76.1 54.8 65.3 65.6 68.8 71.2 64.6 44.3 46.8 72.7 52.8 31 32.2 79.5 (101) (102) (104) (105) 20. copper alloys.8 57.1 24 24.3 58.2 55.8 84.8 62.1 76.3 64 64.4 71.6 80.5 68 HRA 69.3 57.3 80.7 85 85.5 45.6 74.1 27.3 66.3 34.5 63.5 91.3 21.9 79.7 55.3 53 53.8 82.8 42.8 25.com T.9 75.3 22.5 94 95 96 96.8 41.5 51.5 90.8 58.7 65.8 66.3 35.8 78 78.1 51.1 63.2 65.3 56.7 71. 1) Calculated with: HB = 0. www.8 73.3 72.5 74.7 77 77. 5.9 66.8.7 61.8] (6.2 61.1 61 61. Rockwell A for sintered steel and Rockwell B for soft steels.2 29.8 50.4 83.8 64.7 60.3 81.5 64.4 78.6 78.1 46.4 77.1 74. etc.2 33.4 27.7 98.bossard.2 58.7 63.065 © 2005 by Bossard Home .2 Brinell hardness1) Rockwell hardness HRB 361 371 380 390 399 409 418 428 437 447 (465) (466) (475) (485) (494) (504) (513) (523) (532) (542) (551) (561) (570) (580) (589) (599) (608) (618) HRC 38.7 56. For high alloyed and / or cold headed steels [4.6 26.2 23.7 85. The referee method per ISO 898/1 is the Vickers method.5 93.95 · HV The Vickers testing method is applicable over a wide hardness range.2 62. The Brinell hardness method extends over a wide hardness range too. low alloy steels and cast steels in the hot formed and heat treated condition.8 105 109 114 119 124 128 133 138 143 147 152 156 162 166 171 176 181 185 190 195 199 204 209 214 219 223 228 233 238 242 247 252 257 261 268 271 276 280 285 295 304 314 323 333 342 352 HRC HRA 41 48 52 56.8 28.7 43.8.3 70.6 The figures in brackets represent hardness values beyond the defined scope of the standardised hardness test but which are frequently used as appoximate values in practice. The Rockwell C method is suitable for hardened steels. A1 to A4) there are considerable differences to be expected Tensile Vickers strength hardness N/mm2 [F ≥ 98 N] 255 80 270 85 285 90 305 95 320 100 335 105 350 110 370 115 385 120 400 125 415 130 430 135 450 140 465 145 480 150 495 155 510 160 530 165 545 170 560 175 575 180 595 185 610 190 625 195 640 200 660 205 675 210 690 215 705 220 720 225 740 230 755 235 770 240 785 245 800 250 820 255 835 260 850 265 865 270 880 275 900 280 915 285 930 290 950 295 965 300 995 310 1030 320 1060 330 1095 340 1125 350 1155 360 1190 370 Tensile Vickers strength hardness N/mm2 [F ≥ 98 N] 1220 380 1255 390 1290 400 1320 410 1350 420 1385 430 1420 440 1455 450 1485 460 1520 470 1555 480 1595 490 1630 500 1665 510 1700 520 1740 530 1775 540 1810 550 1845 560 1880 570 1920 580 1955 590 1995 600 2030 610 2070 620 2105 630 2145 640 2180 650 660 670 680 690 700 720 740 760 780 800 820 840 860 880 900 920 940 Brinell hardness1) Rockwell hardness HRB 76 80.7 85 87.8 39.7 81.3 75.7 76.1 89.9 47.1 81.8 70. including reproduction. Rep.P.com T. Rep. Dem. translation and recording and processing in electronic datasystems. of Spain Sri Lanka Sweden Switzerland Syria Tanzania Thailand Trinidad and Tobago Turkey United Kingdom USA Uzbekistan Venezuela Viet Nam Yugoslavia CSK KATS LNCSM DSM DGN MNCSM SNIMA NEN SNZ SON NSF PSI BPS PKN IPQ ASRO SASO PSB SABS AENOR SLSI SIS SNV SASMO TBS TISI TTBS TSE BSI ANSI UZGOST FONDONORMA TCVN SZS Copyright: This catalogue is protected by the laws of intellectual property and competiton.bossard.2006 english group www. © Copyright 2006 by Bossard AG.01.066 © 2005 by Bossard Home .of Korea. All rights are reserved.00–09. CH-6301 Zug Version T.Rep.02.Designations of different national standards according to ISO Tolerances / Tables / Standards Country Abbreviation Country Abbreviation Algeria Argentina Australia Austria Bangladesh Belgium Brazil Bulgaria Canada Chile China Colombia Cuba Cyprus Czech Republic Denmark Egypt Ethiopia Europe Finland France Germany Ghana Greece Hungary India / Inde Indonesia International Iran Ireland Israel Italy Jamaica Japan Kenya IANOR IRAM SAI ON BSTI IBN ABNT BDS SCC INN CSBTS ICONTEC NC CYS CSNI DS EOS QSAE EN SFS AFNOR DIN GSB ELOT MSZT BIS BSN ISO ISIRI NSAI SII UNI JBS JISC KEBS Korea. of Libian Arab Jamhiriya Malaysia Mexico Mongolia Marocco Netherlands New Zealand Nigeria Norway Pakistan Philipines Poland Portugal Romania Saudi Arabia Singapore South Africa.