Fasteners Handbook - Blacks_Catalogue

Fastener HandbookBLACKS FASTENERS LTD AUCKLAND 930c Great South Road T: (09) 589 1036 F: (09) 589 1037 NELSON Corner Brilliant Place and Nayland Road T: (03) 547 5102 F: (03) 547 0189 CHRISTCHURCH 39a Gasson Street, Sydenham T: (03) 365 2460 F: (03) 365 2464 CHRISTCHURCH 521c Blenheim Road, Sockburn T: (03) 348 0340 F: (03) 348 0346 INVERCARGILL 156 Bond Street T: (03) 214 4499 F: (03) 214 4489 Freephone: 0800 652 463 Freefax: 0800 652 464 www.blacksfasteners.co.nz Established 1989 Fastener Handbook Bolt Products This book has been published to help our customers choose the right fasteners for the job. The majority of the information is based on Ajax Spurway Fasteners. The fasteners may vary slightly to other manufacturers. BLACKS FASTENERS LTD accepts no responsibility for any loss due to this publication. This publication is distributed on the basis and understanding that the publisher is not responsible for the results of any actions being taken on the basis of information in this publication nor for any error in or omission from this publication. Index F A S T E Page No. 1 Headmarks (Bolts) 2 Standard Bolt Product Range 3-4 Thread Forms and Fits 5-6 Testing of Bolts and Nuts 7 Strength-grade Designations for Amercian and British Standard Fasteners 8-13 Breaking and Yield Loads 14-15 Bolt Shear Capacity 16-20 Design of Bolted Joints for General Engineering 21-30 Tightening of Bolted Joints 31-35 Tightening of Structural Bolts 36-44 Structural Design using Black's Bolts 45-48 Black's Structural Bolts 49 Black's High Strength Structural Bolts 50-51 Coronet Load Indicators 52 High Tensile Hexagon Bolts 53 Hexagon Head Set Screws 54-55 Metric Hexagon Bolts and Set Screws 56-57 Hexagon Head Bolts 58-59 Cup Head Square Neck Bolts 60 Coach Screws 61 Elevator Bolts Four Peg 62-63 Metric Hexagon Nuts 64 Hexagon Nuts and Hexagon Lock Nuts 65 Nyloc Nuts Metric 66 Nyloc Nuts BSW 67 Nyloc Nuts UNC/UNF 68 Correct Use of Jam or Lock Nuts 69-74 Corrosion Protective Coatings 75-76 Tapping Drill Tables 77 Thread Screw Pitches 78-80 Hardness Conversion Table 81 The Torquing of Stainless Steel 82-83 Mechnical Properties of Stainless 84 Material Compatibility N E R S F A S T E N E R Headmarks S A manufacturer’s brand, usually a letter or symbol on the head of each fastener is mandatory for compliance with the relevant New Zealand Standard. Head Marking The following table indicates the Blacks Fasteners range of stocked bolt products which comply to Australian standards. • • • Mechanical properties Chemical composition Source of manufacture – “Manufacturer’s Identification”. Bolt Type Hexagon Head New Zealand Standard AS 1111 Metric Commercial M Hexagon Head AS 2451 BSW Mild Steel Hexagon Head Precision Metric High Tensile Hexagon Head Unified High Tensile (UNC/UNF) Hexagon Head High Strength 8.8 FJ AS 1110-8.8 metric Grade 5 Imperial AS 2465 (SAE) Grade 8 AS 1252 Structural Cup Head BSW AS 1390 Square Neck M Cup Head Oval Neck Fishbolts AS 1085 Cup Head BSW AS B108 Square Neck M Cup Head Oval Neck Fishbolts (AS E25) Hexagon Head AS 1393 Metric Coach Screws Fasteners your guarantee of quality Fasteners yourindustrial guaranteefasteners of quality industrial fasteners 1 Elevator Bolts B UNC Threads High Tensile Hexagon Head Bolts Grade 5 BZ High Tensile Hexagon Head Set Screws Grade 5 High Tensile Hexagon Head Bolts Grade 8 BZ High Tensile Hexagon Head Set Screws Grade 8 B AS 2465 BZ AS 2465 B AS 2465 BZ AS 2465 B AS 2465 BZ AS 2465 B AS 2465 BZ AS 2465 UNF Threads High Tensile Hexagon Head Bolts Grade 5 BZ High Tensile Hexagon Head Set Screws Grade 5 High Tensile Hexagon Head Bolts Grade 8 High Tensile Hexagon Head Set Screws Grade 8 BZ NOTES: 1) Restricted range for some products.Standard Bolt Product Range Table 1 Standard Range Bolt & Nut Product F A Standard Range Bolt only S T E N E R S Australian Standard ISO Metric Threads Commercial Hexagon Head Bolts BGZ Commercial Hexagon Head Set Screws AS 1111 BGZ AS 1111 Cup Head BGZ AS 1390 Cup Head Oval Neck Fishbolts B AS 1085 Precision Hexagon Head High Tensile Bolt Property Class 8.Fish Bolt B (AS E25) Four Peg .8 BG Hexagon Head Coach Screws AS 1252 GZ AS 1393 BSW Threads Mild Steel Hexagon Head Bolts BGZ Mild Steel Hexagon Head Set Screws AS 2451 BGZ AS 2451 Cup Head BZ AS B108 Cup Head Oval Neck . 2) B = Plain finish 3) G = Galvanised finish to AS 1214 4) Z = Zinc Plated finish to AS 1897 Fasteners your guarantee of quality industrial fasteners 2 .8 BZ B AS 1110 Precision Hexagon Head High Tensile Set Screws Property Class 8. Check availability of particular sizes.8 BZ AS 1110 Precision Hexagon Head High Tensile Fine Thread Bolts Z Precision Hexagon Head High Tensile Fine Thread Set Screws Z High Strength Structural Bolts Property Class 8. are manufactured to the Australian standard (AS) specifications which are designed to ensure interchangeability with corresponding International (ISO) American (ANSI/ASME) and British (BS) standards. Table 2 Thread Specifications Screw thread system Specification Title British Standard Whitworth B.S. Standard products. unless specifically requested. Other dimensional features conform with the specifications listed in Table 1. Parallel Screw Threads of Whitworth Form Unified National Fine UNF AS 3501 AS 3635 Unified Screw Threads ISO Metric Coarse Pitch Series AS 1275 Metric Screw Threads for Fasteners ISO Metric Fine Pitch Series AS 1721 General Purpose Metric Screw Threads Unified National Coarse UNC Screw Thread Terminology Standard Thread Forms FIGURE 1 FIGURE 2 FIGURE 3 FIGURE 4 FIGURE 5 FIGURE 6 Fasteners your guarantee of quality industrial fasteners 3 .F A S T E N E R Threads Forms & Fits S All standard Blacks screws are made in accordance with the latest issues of the thread specifications shown in Table 2.W. allowances for fit being applied to the external (bolt) thread. Bolt Nut Free Normal 1A 1B 8g 7H Bolt Nut Medium Normal 2A 2B 6g 6H Represents a precision quality screw thread product. recommended only for applications where a close snug fit is essential. The clearance permits rapid assembly without excessive play. Exception is made for galvanised fasteners where an additional F A S T E N E R S allowance is made in the nut (which is tapped after galvanising) to accommodate the thick coating on the male thread. (See note. Only Free/1A/8g and Medium/2A/6g threads should be galvanised. Fasteners your guarantee of quality industrial fasteners 4 .Threads Forms & Fits Thread Fits Screw thread standards provide for various classes of fit using a hole basis tolerancing system (ie maximum metal limit of the internal thread is basic size). Table 3 Thread class Whitworth United (BSW & (UNC & BSF) UNF) ISO Metric Application Applies to the majority of nuts and bolts of ordinary commerical quality. Bolt Nut Close Medium 3A 3B 4h 5H An exceptionally high grade threaded product. Table 3 consists of the three thread class combinations which apply to the majority of commerical applications.) NOTE: These higher classes do not make any allowance for fit (ie maximum bolts and minimum nuts have a common size) and under some circumstances selective assembly may be necessary. it is the usual practice to test bolts in their full size to more adequately reproduce the conditions under which they will be used in service. are determined on machined test pieces. This consists of applying a proof load (derived from a “proof load” stress) with the bolt head supported on a parallel collar. the bolt load is calculated from the tensile strength of the material. Tensile Stress Areas for common sizes and thread forms will be found in Tables 5-11. The test. elongation. Standards Association of Australia. British Standards Institution. tensile strength. and for bolts with short or no plain shank length. 0. The load is calculated from the tensile strength of the material and the Tensile Stress Area of the thread. and a tapered or wedge collar for the second stage when it is broken in tension. as indicated above. The angle of the wedge is varied for bolt diameter and grade. The bolt length is measured accurately before and after application of the proof load. This procedure of tensile testing bolts in their full size is recognised and adopted by many standardising bodies. The bolt is assembled as described previously but with the head supported on a tapered wedge collar.5 micrometers allowance is made for errors of measurements. A 0.2% yield stress. This test provides a guide to the load to which the bolt will behave elastically.F A S T E N E R S Testing of Bolts & Nuts The normal tensile properties of metals. is carried out in two stages: (1) Proof Load Test. including the International Organisation for Standardisation (ISO). therefore. in addition to meeting the specified minimum breaking load. proof stress.0005” or 12. The bolt head must. The bolt is loaded until it fractures. fracture must occur in the thread or plain shank with no fracture of the head shank junction. The Tensile Stress Area is the area calculated from the mean of the minor and pitch diameters of the thread. and the breaking load must be above the specified minimum. American Society for Testing and Materials (ASTM) and Society of Automotive Engineers (SAE). The bolt head is initially supported on a parallel collar for the proof load test. (2) Wedge Tensile Test. and the Tensile Stress Area of the thread. In this test. The bolt is screwed into a tapped attachment (Figure 7) with six full threads exposed between the face of the attachment and the unthreaded shank. reduction of area. but in most cases for bolts up to 1" or 20mm diameter it is 10°. The test requires that. While these properties and testing methods can be applied to bolt materials. be capable of Fasteners your guarantee of quality industrial fasteners 5 . It is required that the bolt shall not have permanently extended. (3) Proof Load Test for Nuts. This latter requirement provides a very practical test for ductility. This “rule of thumb” still applies for products to the older standards such as BSW commercial and unified high F A S T E N E R tensile precision nuts. The nut is assembled on a hardened. it is usual to carry out hardness tests on the top or bottom face of the nut. Again. This is also referred to as a Proof Load Test and it was traditional for the nut “Proof Load Stress” to be the same as the specified minimum tensile strength of the mating bolt. a mating bolt of the same strength class up to its actual (not specification minimum) yield stress without the assembly failing by thread stripping.Testing of Bolts & Nuts conforming with the required wedge taper angle without fracturing at its junction with the shank. This is performed on a cross section through the bolt thread at a distance of 1 x diameter from the end. The nut must withstand this load without failure by stripping or rupture. Metric nuts to AS 1112 . Fasteners your guarantee of quality industrial fasteners 6 S . a hardness test is carried out. and be removable from the mandrel after the load is released. To satisfy this design requirement both the thickness/diameter ratio and proof load stress were increased and now vary with diameter. where nut proof loads exceed the capacity of available. The preferred method of testing nuts follows that of bolts in adoption of a test in full size to measure the load which the nut will carry without its thread stripping.1980 were designed with greater knowledge of bolt/nut assembly behaviour to satisfy the functional requirement that they could be used to tighten (by torque). Where the capacity of available testing equipment does not permit testing of bolts in full size. threaded mandrel (Figure 8) and the proof load applied in an axial direction. 000 55. Medim carbon alloy steel. 3. 2. quenched and tempered. quenched and tempered.000 65.000 85.000 120.000 105.000 C25-C40 to 1" 120.2 (Note 3) 7 (Note 4) 1/4" to 11/2" 133.000 85.1 (Note 2) No. SAE Grade Head Marking 1/4" 1 to 11/2" 1/4" to 3/4" over 3/4" to 11/2" 2 4 Diameter None (studs only) 1/4" to 11/2" Tensile Strength lbf/in2 (min.000 C33-C39 8. Fasteners your guarantee of quality industrial fasteners 7 .000 120.000 C33-C39 1/4" to 11/2" 150.000 B70-Bl00 74. Thread rolled after heat treatment.1 8.000 120.000 33.000 60. 5. quenched and tempered.6 to 5/8" 120.000 C25-C34 C19-C30 5.000 C28-C34 8 (Note 5) 1/4" to 11/2" 150.000 C22-C32 5 (Note 1) 1/4" to 1" Over 1" to 11/2" 120. 4.000 74. quenched and tempered. Medium carbon steel.000 105.F A S T E N E R S Strength-Grade Designations for American and British Standard Fasteners Table 4 American SAE Standard (AS 2465 is identical for Grades 2. quenched and tempered. Sems (captive washer) assemblies.000 85. Low carbon boron steel. These are of low or medium carbon steel. 8 only).000 C26-C36 1/4" 5.2 None (studs only) 1/4" to 1" NOTES: 1.) “Proof Load” Rockwell Stress lbf/in2 Hardness 60.000 B80-Bl00 B70-Bl00 115. 5.000 C32-C38 150.000 33. Medium carbon alloy steel. 6 9.21 157270 700 * See introductory paragraph to this section for definition of “Stress Area”. Sq. in.7 Tonf lbf Kn 4.6969 0.4 2.12 20420 90.3 13.3039 0.in.0941 0.3 3/4 BSW 0.40 1.0683 0.18 4880 21.Breaking & Yield Loads When bolts are broken in tension.0141 0.1214 0.47 3290 14.6 5/8 BSW 0. that the actual tensile breaking load of a bolt is higher than the figure calculated in this manner.4218 0.7 7/8 BSW 0.311 2.96 3/8 BSW 0.05 38190 170 11/8 BSW 0.00 29120 129 1 BSW 0. however.70 32920 146 27.1069 1. and this is now generally accepted as the basis for computing the strength in tension of an externally threaded part.766 11.300 21.51 1140 5.410 13/4 BSW 1.0779 1. American Society of Automotive Engineers (SAE).0171 0.8942 0.227 3. This calculation gives a figure which is known as the “Stress Area”.96 15590 69.0272 0. and it might be expected that the breaking load could be calculated on the basis of the material strength and the area at the root of the thread.1 3. (to 3/4” diameter) 15 tonf/in2 min. 16 tonf/in2 min.0321 0.35 14220 63.22 4970 22.0527 0. F A S T E N E R diameters of the thread.2032 0.48 1070 1/4 BSW 0.464 6.) lbf Kn 3/16 BSW 0.) Tonf Breaking Load of bolt (min.7 7/16 BSW 0.27 600 2.753 1.60 64060 285 53.88 8690 38. 28 tonf/in2 min.90 2010 5/16 BSW 0. Tests have proved.45 88370 393 1. and the most accurate estimate is based on the mean of the pitch and minor Blacks BSW Bolts AS 2451 Table 5 Based on: Size Tensile Strength Yield Stress = = Area of Stress Root of Area of Thread Thread* Sq.5542 0.12 0. (over 3/4” diameter) Yield Load of bolt (min.84 1880 8.41 21080 93.39 119590 532 2 BSW 2.907 28. British Standards Institution.77 8.2 6.8 1/2 BSW 0.38 12050 53.50 25760 114 21. recommendations and in specifications issued by the Standards Association of Australia.73 0.980 14.63 8130 36.60 84220 375 70. Stress Area is adopted for strength calculations in I.0457 0.15 47370 211 39. breaking will normally occur in the threaded section.0 2.99 6700 29.336 5.9 17.508 37.608 9.1385 2.71 3830 17.25 2800 12.42 47980 214 11/4 BSW 0.40 61480 273 11/2 BSW 1. Fasteners your guarantee of quality industrial fasteners 8 S .O.S. 16 0. lbf kN 1/4 UNF 0. Yield Stress = 92000 lbf/in2 min. Sizes 11/8” .0141 0.95 6610 29.11/2” incl. = 105000 lbf/in2 min.in.43 Kn 4.37 9780 43.39 3110 13.581 117000 520 166000 738 85. Sizes 11/8” .0321 0.3 5/16 UNF 0. Other sizes to special order.90 13220 58.74 19570 87.0 30700 137 3/4 UNF 0.0580 4900 3/8 UNF 0.0364 3100 13.7 3/8 BSW 0.84 1880 8.4 5.78 6230 27.32 1/4 BSW 0.3039 0. lbf Kn Tonf 3/16 BSW 0.0457 0.336 4.1” incl.44as 1000 lbf 4.1069 1.0941 0.521 1. Sizes 11/8” .1486 0.11/2” incl.69 1540 1.0171 0 22 500 2.625 0.1385 1.4 * See introductory paragraph to this section for definition of “Stress Area”.41 940 5/16 BSW 0.073 79400 353 112700 501 11/2 UNF 1.8 3/4 BSW 0.9 5/8 BSW 0.8 2.60 8070 35.11/2” incl. in. Blacks stock range shown in bold face.1 10500 7/16 UNF 0.37 3070 13.0527 0.1” incl.1” incl.0272 0.22 0.1 2.) Tonf Breaking Load of Bolt (min.812 0.) Sq. Yield Load of Bolt (min.509 43300 193 61100 272 1 UNF 0. 81000 lbf/in2 min.227 2.2032 0. Sizes 1/4” .03 4540 20.8 lbf kN 4350 19.0779 1.7 1/2 BSW 0. 13 tonf/in2 min.F A S T E N E R Breaking & Yield Loads S Blacks Cup Head BSW Bolts AS B108 Table 6 Based on: Tensile Strength = Yield Stress = Size Area of Stress Root of Area of Thread Thread* 26 tonf/in2 min.83 * See introductory paragraph to this section for definition of “Stress Area”.1090 0.) Sq.351 0. Sizes 1/4” .0 6.9 3.024 1.2 7/16 BSW 0.0524 0.0326 0.8 6950 30.1187 10100 46. Blacks Unified High Tensile Hexagon Head Bolts and Set Screws (AS 2465/SAE Grade 5) Table 7 Based on: Tensile Strength = 120000 lbf/in2 min.373 31700 141 44800 199 7/8 UNF 0.5 19200 5/8 UNF 0.856 63300 282 89900 400 11/4 UNF 1. Proof Load Stress = 85000 lbf/in2 74000 lbf/in2 Size Area of Root of Thread Stress Area of Thread* (827 MPa) (724 MPa) (634 MPa) (558 MPa) (586 MPa) (510 MPa) Sizes 1/4” .9 14200 63.240 0.0683 0.80 4030 17.663 56400 251 79600 354 11/8 UNF 0.256 21800 97.2 1/2 UNF 0.480 0. Sq.0809 0.9 33. Sq.5 8. in. Proof Load of Bolt Breaking Load of Bolt (Min.7 44. in.1599 13600 60. Fasteners your guarantee of quality industrial fasteners 9 .0878 7450 21.1214 0.01 2270 10. Breaking & Yield Loads F A S T E N E R Blacks Hexagon Head Bolts and Set Screws (AS 2465/SAE Grade 5) Table 8 Based on: Tensile Strength = 120000 lbf/in2 min.0524 4450 19.11/2” incl.0775 6600 29.3 12800 56.693 0. Blacks stock range shown in bold face.0 3/8 UNC 0.334 28400 126 40100 178 7/8 UNC 0.1419 12100 53.226 19200 85.) Sq.763 56500 251 80100 356 11/4 UNC 0.0318 2700 12.294 1.606 51500 229 72700 323 11/8 UNC 0. Sizes 1/4” . Proof Load of Bolt Breaking Load of Bolt (Min. in. Proof Load Stress = 85000 lbf/in2 74000 lbf/in2 Size Area of Root of Thread Stress Area of Thread* (827 MPa) (724 MPa) (634 MPa) (558 MPa) (586 MPa) (510 MPa) Sizes 1/4” .0454 0.1” incl.1063 9050 40.462 39300 175 55400 246 1 UNC 0. Sq. lbf lbf kN 1/4 UNC 0.969 71700 319 101700 452 11/2 UNC 1.0269 0. Sizes 11/8” .405 104000 463 147500 656 75.302 0.0678 0. Fasteners your guarantee of quality industrial fasteners 10 S .8 6300 28. Sizes 11/8” .1” incl.4 7/16 UNC 0.9 1/2 UNC 0. in.419 0.4 27100 121 3/4 UNC 0.8 17000 5/8 UNC 0.6 * See introductory paragraph to this section for definition of “Stress Area”.11/2” incl.0 kN 3800 16.1257 0. Other sizes to special order. Yield Stress = 92000 lbf/in2 min. Sizes 1/4” .202 0.4 9300 41. = 105000 lbf/in2 min.9 5/16 UNC 0.11/2” incl.890 0.551 0.0933 0.1” incl. 81000 lbf/in2 min. Sizes 11/8” . 0524 6300 28.F A S T E N E R Breaking & Yield Loads S Blacks Hexagon Head Bolts and Set Screws (AS 2465/SAE Grade 8) Table 9 Based on: Tensile Strength = 150000 lbf/in2 min.663 79600 354 99400 442 11/8 UNF 0.302 0.0809 0.1599 19200 85.373 44800 199 56000 249 7/8 UNF 0. Yield Stress = 130000 lbf/in2 min.0269 0.1187 14200 63.1419 17000 5/8 UNC 0. (1034 MPa) Sizes 1/4” .419 0.4 11600 46.0326 0.0933 0. in.7 13200 58.480 0.0454 0.462 55400 246 69300 272 1 UNC 0. Sq.0775 9300 41.606 72700 323 90900 354 11/8 UNC 0.7 3/8 UNF 0.9 3/8 UNC 0. lbf kN lbf kN 1/4 UNF 0.351 0.3 5450 24.0580 6950 30. in.1063 12800 56.4 * See introductory paragraph to this section for definition of “Stress Area”.969 116300 517 145400 573 11/2 UNC 1.0524 0.2 1/2 UNC 0.7 7/16 UNF 0.693 0.2 21300 85.) Sq.3 5/16 UNC 0.0318 3800 16.763 91600 407 114400 457 11/4 UNC 0.9 8700 38.11/2” incl.1090 0.226 27100 121 33900 137 3/4 UNC 0.509 61100 272 76400 340 1 UNF 0.256 30700 137 38400 171 3/4 UNF 0.9 15900 63.625 0. Fasteners your guarantee of quality industrial fasteners 11 .0678 0.0878 10500 46.024 1.0364 4350 19.405 168600 750 210800 844 75.2 17800 1/2 UNF 0.294 1. (896 MPa) Proof Load Stress = 120000 lbf/in2 (827 MPa) Size Area of Root of Thread Stress Area of Thread* Proof Load of Bolt Breaking Load of Bolt (Min.9 4750 19.551 0.2 5/16 UNF 0.0 7850 30.202 0.856 102700 457 128400 571 11/4 UNF 1.581 189700 844 237200 1055 1/4 UNC 0.1486 0.073 128800 573 161000 716 11/2 UNF 1.4 24000 107 5/8 UNF O.6 79.334 40100 178 50100 199 7/8 UNC 0.890 0.812 0.521 1.240 0.7 7/16 UNC 0.1257 0. 8 14118 M20 225 245 55.6) Table 10 Based on: Size Tensile Strength Yield Stress Proof Load Stress = = = 400 MPa min 240 MPa min 225 MPa Area of Root of Thread Tensile Stress Area of Thread mm2 mm2 (58015 lbf/in2) (34810 lbf/in2) (32635 lbf/in2) Proof Load of Bolt kN lbf Breaking Load of Bolt (Min.0 13.2 3.3 7936 62.7 14.1 4.Breaking & Yield Loads F A S T E N E R S Blacks Metric Hexagon Commerical Bolts and Screws (AS 1111 Property Class 4.24 M8 32.04 1807 8.0 2923 23.2 84.8 36.68 1277 M6 17.7 7576 M16 144 157 35.4 17850 141 31698 M30 519 561 126 28326 224 50357 M36 759 817 184 41365 327 73513 M42 1050 1120 252 56652 448 100714 M48 1380 1470 331 74412 588 132188 M56 1910 2030 458 102963 812 182545 M64 2520 2680 605 136009 1072 240995 Fasteners your guarantee of quality industrial fasteners 12 .3 19.6 3282 M10 52.20 719 5.9 20.52 1016 8.2 5216 M12 76.0 4271 33.1 12387 98.6 1852 14.0 22031 M24 324 353 79.3 58.) kN lbf M5 12. ) kN M5 M12 Proof Load of Bolt lbf M16 144 157 M20 225 245 147 33047 203 45636 M24 324 353 212 47660 293 65869 M30 519 561 337 75760 466 104761 M36 759 817 490 110156 678 152421 * See introductory paragraph to this section for definition of “Stress Area”. 830 MPa min (120380 lbf/in2) Sizes M20 .0 33.9 10993 67.8) Table 11 Based on: Tensile Strength = = Yield Stress = = Proof Load Stress = = Size 800 MPa min (116030 lbf/in2) Sizes M5 .2 M6 17. Fasteners your guarantee of quality industrial fasteners 13 . 600 MPa (87025 lbf/in2) Sizes M20 . 660 MPa min (95725 lbf/in2) Sizes M20 .F A S T E N E R Breaking & Yield Loads S Blacks Metric Hexagon Precision Bolts and Screws (AS 1110 Property Class 8.23 1850 11.M36 incl. Area of Root of Thread Tensile Stress Area of Thread* mm2 mm2 lbf kN 8.7 14.3 48.M16 incl.4 15152 91. 640 MPa min (92825 lbf/in2) Sizes M5 .35 2552 11.4 10431 84.9 20.1 M8 32.6 2608 16.M16 incl.2 6564 58.M36 incl.7 7576 46.M36 incl.1 3619 36.6 21.0 20458 125 28101 12. 580 MPa (84120 lbf/in2) Sizes M5 .3 76.2 4766 29.2 Breaking Load of Bolt (Min.M16 incl.8 M10 52. Table 13 gives guidance for AS 1250 and AS 4100 values 2.Bolt Shear Capacity F A S T E N E R S Table 12 Specification AS 1111 AS 2451 AS 1110 Prop. Fasteners your guarantee of quality industrial fasteners 14 . Based on nominal diameter of shank. Multiple bolt joints are subject to an “unbuttoning effect”. Tabulated values are for failure. 14% for joints 500-1200mm length. Cl 10.9 AS 2465 Grade 8 Minimum Breaking Load in Single Shear – kN 1 2 Shank3 Thread Shank3 Size M6 1/4" M8 Shank3 Thread Coarse 7 4 14 9 5 16 9 13 8 25 16 Fine 9 11 Thread Coarse 18 12 20 11 33 21 Fine 14 5/16" 13 8 26 15 17 32 19 22 3/8" 19 12 37 23 27 46 28 34 20 13 39 26 51 34 26 16 50 31 28 19 57 38 M10 7/16" M12 1/2" 36 39 50 21 65 42 50 36 101 72 5/8" 53 35 102 67 80 128 84 100 3/4" 77 53 147 101 117 184 126 146 79 56 163 117 204 146 7/8" 105 73 201 140 160 251 175 113 81 235 168 294 211 M20 M24 82 52 131 94 45 34 M16 50 63 74 62 200 1" 137 97 262 184 208 327 230 260 11/8" 173 121 332 202 237 414 289 338 M30 177 130 368 270 459 337 M36 254 190 529 395 662 493 308 226 589 377 736 539 11/2" 444 634 NOTES: 1. 43% for joints over 1200mm. 3. Cl.8 AS 2465 Grade 5 AS 1110 Prop. AS 1511 reduces design shear capacity. AS 1250 states that this should be considered when more than 5 bolts are aligned in the direction of the force. 8. Refer to applicable Code for permissible Design Stress. The values shown are for a single shear plane and may be compounded for multiple shear planes. AS 4100 progressively reduces design shear capacity by 25% for joints 3001300mm length and longer. used a value 290 MPa (=91% of the specified minimum value) which would be experienced by the fastener under the 80 year mean return wind. Reference SAE J417.6 752. For mild steel bolts the relevant criterion (see Note 4 above) is generally .0 410. Other load factors apply for other actions eg.28 1. 5. check that both maximum and minimum are suitable.2 198.0 431.3 238. This ratio was established on tension loaded lap joints.8 181.19 257. Thus the “Design Capacity Shear Stress” shown here to facilitate comparison with the previous rule is 80% of the minimum shear stress at failure shown in column 2. wind etc.1 512.33Fyf. They previously used the 30 year mean return wind and had some towers blow down. 4.038 = lbf/in2. Basis is ultimate shear stress equals 62% of ultimate tensile strength.9 496.4 452.17 206.6 636. Fasteners your guarantee of quality industrial fasteners 15 .1 1. the value here would be 297.25 on dead loads and 1. With Load Factors of 1.5 260.5 396.6 – M16 M18 – M36 AS 2465 Unified Grade 5 1/4" – 1" 11/8" – 11/2" AS 2465 Unified Grade 8 AS 1110 Property Class 10.8 M1.5)6 (76.7 448.5 on live loads it can be seen that bolt loading is still conservative compared to their ultimate capacity although less so than under AS 1250 rules.25Fuf.5 1.6 452.8 654.3 214.34 (81. the available bolt shear area (threads or shanks) and a “Capacity Factor” which is 0.0 514.7 512.5 1. earthquake. Maximum shear stress at failure is based on imputed maximum tensile strength.31 1.F A S T E N E R Bolt Shear Capacity S Table 13 Shear Stress at failure1 (Mpa) Min Max Ratio2 248.1 752. Geometric effects on compression loading similar joint configuration can give apparent bolt shear capacity 9% higher.1 654.not the actual shear stress which may not be applied to the bolts.17 1. estimated from specified maximum hardness. 7. Reference AS 4100-1990.6 MPa but 320 MPa is shown as it is a specified requirement of AS 1559.8 320.6 AS 2451 BSW Low Tensile 1/4" – 3/4" 7/8" – 1" AS 1559 Tower Bolt AS Property Class 5.8 AS 1110 Property Class 8.0 207. MPa x 145.1 589. Maximum Permissible Shear Stress in design is the lesser of .6 – 431.6)6 112.8 for the Strength Limit State Criterion.0 214. in lattice tower design.69 1. 9. For overload protection application.8 267. AS 4100 does not express stress values but extends the data to a “Design Resistance Capacity” taking account of the length of the joint (see Table 12 Note 2).4 267.1 1. Some Design Authorities have for over 5 years. 10.9 515.9 AS 1250–1981 AS 4100–1990 Maximum Maximum Permissible “Design Design Shear Capacity Stress Shear Stress”5 (MPa)4 (MPa) NOTES 1. 3.28 1.74 79. and represents the stress value which the factored actions (loads) acting on the bolts may not exceed . Maximum equals minimum (Table 12) value times ratio.0 644.28 130. On the basis of Note 1. Factoring the specification minimum shear stress would give a value of 256 MPa.07 322. 2. 8.0 258.69 – 1. kN x 224.809 = lbf.27 200.2 359.8 Bolt Type AS 1111 Property Class 4. AS 2451 does not specify Fyt so the values shown are from Blacks Fasteners Ltd data.8 411.9 641.33Fyf and 0. 6. Joints Carrying Direct Tensile Loads (1) Safety Factor. Fewer bolts can be used to carry the same total load. the preload on each bolt should be taken according to the bolt size and bolt material as shown in Tables 18 to Fasteners your guarantee of quality industrial fasteners 16 .Design of Bolted Joints for General Engineering F A S T E N E R S Types of Loading on Joints Examine the forces being applied to the joint to decide which of the following types fits the conditions. In cases where fine adjustment is needed. Providing bolts are tightened to the torque specified in Tables 18-23 there should be no tendency to loosen under conditions of vibration with either coarse or fine threads. can. 9). 12). start more easily. a) Selection of Tensile Strength of Bolts Bolted joints in which strength is the main design consideration. Safety Factor = Sum of preload on all the bolts comprising the joint Design applied load For design purposes. but refers to the factor by which the sum of the preload on all the bolts comprising the joint exceeds the design load applied. Except in the case of the flexible gasket joint. The coarse threads provide adequate strength and great advantages in assembly over fine threads. c) Flexible gasket joints for sealing liquids or gases under pressure (See Fig. Types 1 and 2. be more economically designed when a high tensile bolt is used rather than a mild steel bolt. but also machining where less holes are drilled and tapped. giving rise to savings not only from the cost of a smaller number of bolts. and require less time to tighten. Apply a safety factor according to the nature of the loading. Joints carrying direct tensile loads (See Fig. the bolts should still be preloaded to 65% of their yield stress using the recommended torque values as set out in Table 18-23. particularly in awkward positions. and assembly where less time is taken. the safety factor on a bolt differs from most other applications in that it does not affect the stress of the bolt. in most cases. The former are less liable to become cross threaded. b) Joints carrying loads in shear (See Fig. Regardless of the nature of the load. Selection of Coarse and Fine Threads In practically all cases the coarse thread is a better choice. 10-11). the fine thread should be used. etc. Number of Bolts. This information is provided for guidance only. Friction type joints. (4) Specify Tightening Torque. secondary bending stresses in the bolts and bolted members are reduced to a minimum.F A S T E N E R S Design of Bolted Joints for General Engineering 23 and the safety factor selected from the following table:Table 14 Nature of Loading Safety Factors* Steady Stress 1. By doing this. (5) Positioning of the Bolts. where the load is transferred by the friction developed between the members by the clamping action of the bolts. Joints in which the load is transferred through the bolted members by bearing of the member on the shank of the bolt and shear in the bolt. F is the total required preload and f is the recommended preload (see Tables 18-23) on the bolt for the particular size and material selected.5 4. Joints Carrying Loads in Shear The design procedure for mechanical joints carrying this type of loading can be based on well established practice laid down for structural joints carrying static loads. Ensure that the bolts are fully tightened to the torque recommended in Tables 18-23 for the particular bolt size and material.5 – 2 Repeated Stress gradually applied shock 2 – 3. (2) Total Required Preload†. Bolted joints carrying loads in shear fall into two types:1. provided the design loads are increased by adequate factors to allow for cyclic loads. † Note: At time of publication there are no “Allowable Stress” code provisions for general mechanical engineering design of bolted joints. Total required preload F = S x L (3) Selection of Bolt Material. Fasteners your guarantee of quality industrial fasteners 17 . Bolt Size. the required number of bolts can be determined from – N=F f Where N is the number of bolts. By selecting a suitable bolt size and bolt material.5 – 6 * Applies to joints with direct tensile loads only and assumes all bolts are tightened to 65% of the yield stress. 2. Determine this from safety factor (S) and applied load (L). and must be based on the designer’s experience. The bolts should be placed as near as possible to the line of direct tensile load. shock. These factors will vary considerably according to the application. 25mm clearance) or is fitted in a clearance hole (up to 2-3mm clearance). To achieve this it may be necessary to use more than one row of bolts. Friction Type Joints These joints are made up using high strength bolts fitted in clearance holes and tightened under careful control to develop a preload equivalent or greater than the bolt yield load. Careful consideration should be given to the properties of the material in the bolted members to ensure they are capable of withstanding bearing loads. The allowable values for shear and bearing depend not only on bolt size. is used to compute the required number of bolts to carry the design load. Care must be taken that the pitch of the bolt spacing is sufficient to ensure that the bolted members are not weakened by the F A S T E N E R bolt holes to the extent that they cannot safely carry the load. but also on the tensile strength of the bolt. Staggering of bolt holes can minimise reduction of member capacity. If more than two members are bolted together slightly higher values are permitted in bearing on the central member. whether it be in shear or bearing.Design of Bolted Joints for General Engineering Load Transfer by Bearing and Shear Such joints may be designed using allowable values for shear in the bolts and bearing on the joint members such as those given in AS 1250 or under the limit states provisions of AS 4100. Guidance on bolt shear capacity is given on page 14. General Rules to Reduce Possibility of Bolt Failure Due to Fatigue The following general rules should be observed to minimise possibility of fatigue of bolts under high alternating or fluctuating stresses. Fasteners your guarantee of quality industrial fasteners 18 S . and the area considered for calculating strength in shear is increased by two or four times for bolts in double or quadruple shear. and whether the bolt is in a close fitting machined hole (not greater than 0. and it is well established that this type of joint is considerably stronger than a riveted joint. Tensile strength and yield stress of Blacks bolts can be obtained from Tables 5-11. The lowest strength. Refer to Australian Standard 4100. The mechanism of carrying load is by friction developed between the mating faces. e. (4) Under conditions of extreme vibration the use of locknuts such as the Conelock or Nyloc nut should be considered to avoid possibility of a loosened nut vibrating right off the bolt before detection. and continues to exert virtually the same force on the bolts when additional load is applied to the joint. F = 1. (5) Bolt head and nut should be on parallel surfaces to avoid bending.F A S T E N E R S Design of Bolted Joints for General Engineering (1) Most Important. so the design procedure must be modified accordingly. (3) Rolled threads are preferable to machined threads. Q = APS (2) Total Preload Required. W=Q+F (4) Select Bolt Material. Flexible Gasket Joints for Sealing Liquids or Gases Under Pressure This type of joint differs from the two preceding types in that the stress in the bolt varies with the working load. Determine the design load Q on the joint by multiplying the effective area A on which the pressure is acting by the liquid or gas pressure P by S where S is the safety factor selected from Table 14. c) In extreme cases a “waisted shank” bolt can be considered. (1) Design Pressure Load. Tighten bolt effectively to ensure an induced tension or preload in excess of the maximum external load.1Q (3) Total Design Load on Bolts. Q add 10%. and this is the sum of the preload F that should be applied to the bolts comprising the joint. F = Q + 10Q 100 i. (6) Non axial bolt loading producing a “prising” action should be avoided where possible. b) Use of small high strength bolts in preference to larger low strength bolts. (2) Bolt extension in tightening should be high. This is because the flexible gasket material has a much lower elastic modulus than the bolt. giving the total design load W on the bolts. From the following table of yield stresses select the bolt material. This can be achieved by:a) At least 1 x bolt diameter of “free” thread length under the nut. The resulting effect is that the working load is added to the bolt preload in this case. To the design pressure load. Fasteners your guarantee of quality industrial fasteners 19 . In the case of a flexible gasket type of joint the design pressure load Q on the joint is added to the preload F on the bolts. 600 248 232 Blacks Metric Commerical Bolts 32. metal to metal pressure tight joints. as these are not subject to fatigue.8 Bolts 95.900 Over 3/4” 33.806.000 827 (5) Select Bolt Size and Determine Number of Bolts. It is therefore desirable to use wherever possible.Design of Bolted Joints for General Engineering F A S T E N E R S figure T for the bolt size and material selected listed in Tables 18-23 must be reduced by multiplying by a factor of 0. and under rapidly fluctuating loads they can be subject to fatigue. Metal to Metal Pressure Tight Joints The stress in the bolts in a flexible gasket type joint varies with load.630 225 Blacks Metric Precision PC 8.8 T Proof Load Stress lbf/in2 MPa Blacks AS 2451 Bolts – 1/4” – 3/4” 35. (see Tables 5-11) determine the number of bolts N from the yield stress Y and the total design load W on the bolts. Table 15 Bolt Type t = 0.725 660 Blacks SAE Grade 5 High Tensile Bolts – 1/4” – 1” 85. Number of bolts required N = W YAs (6) Setting of Tightening Torque. From the desired bolt size and corresponding Stress Area “As”. The design procedure for a metal to metal pressure tight joint is exactly the same as for joints carrying direct tensile loads once the pressure load is determined.000 586 Blacks SAE Grade 8 High Tensile Bolts 120. Tightening torque to be applied to bolts of a flexible gasket type of joint. In this case the bolts can only be tightened to a preload well below the yield stress so the torque Fasteners your guarantee of quality industrial fasteners 20 . the mating faces will not separate until the externally applied load exceeds the total preload. have the same modulus. i. 14) or by a combination of these.e. Thus cyclic external load is experienced more as a change in pressure at the joint face than a change of tension in the bolt and in a well designed joint. Methods of Control of Bolt Tightening Several methods are available for controlling the establishment of a desired level of preload in bolts with the cost rising with increasing accuracy more or less as indicated Fasteners your guarantee of quality industrial fasteners 21 . It is true enough to be important even when the joint members and bolt are of the same material (e. The static load capacity of the joint will be determined largely by the size. 13). strength grade and number of bolts installed.g. The capacity of a bolted joint to maintain integrity indefinitely under dynamic loading is dependent on installing the bolts with sufficient tension to prevent relative movement of the joined members. This concept is valid when the joint members are stiffer (suffer less strain under a given force) than the bolt shank.F A S T E N E R S Tightening of Bolted Joints How a Bolted Joint Carries Load A bolted joint can carry loads in tension (Fig. so that the joint can’t separate until the bolt length increases and the bolt length can’t increase until the tension in it exceeds the preload (assuming service temperature below the creep range). the stress range in the bolts will be below their fatigue endurance limit.. Tension The external load is resisted directly by bolt tension. because the area in compression between the bolt head and nut is much greater than Shear The pre-load in the bolt(s) clamping the members together produces friction between them which resists the external load. the area of the bolt shank in tension and so compresses much less than the bolt extends at any given bolt tension. steel). If the joined members are rigid and the bolts are pretensioned. in shear (Fig. This is because stress and strain are fundamentally related (the relationship constant is called Young’s modulus in the range of elastic behaviour). When the frictional load transfer capacity is exceeded the ultimate capacity of the joint will be determined by shear on the fasteners and bearing on the joined members. The external force which this friction is capable of resisting without movement is proportional to the preload in the bolts and the coefficient of friction on the mating surfaces. Nyloc or Conelock nuts are recommended for joints where such pre-tensioning is not applicable and as an added insurance against loss of the nut. This requirement will give Torquing of Bolts and Nuts The purpose of controlling the torque applied to a fastener assembly is to induce a desired level of tensile force in the bolt (equals clamping force on the joint). the use of torque wrenches is the most common method of pre-load control because of simplicity and relative economy. Power tools are more productive when large numbers of bolts are to be tightened and may be pneumatic. The 65-75% of Proof Load level of pre-tension is sufficiently conservative to give reasonably reliable torque controlled tightening with indefinite Fasteners your guarantee of quality industrial fasteners 22 . Unless limited by some characteristic of the joint (e. should the initial pre-tension be lost. the amount of tension aimed for in general engineering practice is 65-75% of the minimum elastic capacity (proof load) of the bolt. affect the torque-tension relationship and up to +25% variation in pre-load. but generally require tightening of sample bolts in a bolt load measuring device to set a pressure regulator or stalltorque for the desired bolt tension rather than measuring torque directly. Many factors. electric or hydraulic. surface coatingslubrications. (1) Torque Although torque bears no fixed relationship to fastener tension. including surface texture (cut or rolled threads). With manual torque wrenches. loosening of the nut should not be a problem in most applications. thread interference.. etc. Relative Cost 1 11/2 3 31/2 15 20 more accurate control of tension if setting is performed under job conditions with the bolts to be tightened.Tightening of Bolted Joints F A S T E N E R S Table 16 Preload Measuring Method % Accuracy Feel (Operators Judgement) ± 35 ± 25 ± 15 ± 10 ±3–5 ±1 Torque Wrench Turn-Of-The-Nut Load Indicating Washers Fastener Elongation Strain Gauges in Table 16.. has been measured on similar fasteners receiving identical torque. By selecting bolts such that this level of tension is not exceeded by service load on the joint. speed of tightening. the torque may be reset from or read off a built-in scale. Closer control of torque/tension calibration for a particular lot can reduce variation to +15%.g. a soft gasket). Each method has its applications and the choice should be made after an assessment of the particular requirements. it may be desirable to experimentally determine the torque-induced preload relationship. Attention is drawn to the fact that because static friction is greater than dynamic friction. another purchase should be taken early enough to avoid stall before rotation continues. but make use of design features in a bolt head. etc. For bolts with special surface finishes or assembled with anti-seize compounds or heavily greased. (2) Strain Control a) Part Turn Tightening: This method involves imparting a controlled strain or extension to the bolt by measuring relative rotation from the point where the joint members are solidly compacted. The steady impacting of pneumatic tools gives better results. Table 17 lists factors based on averages for the torque-induced preload relationship by which the tabulated figures should be multiplied to correct for the most common surface condition variations. Most plain finish fasteners are supplied with a sufficient oil residue from their processing but plated finishes will generally require oiling or adjustment to the torque recommended in Blacks Fasteners Ltd Technical Data. the torque-induced preload relationship is likely to be altered and the recommendations to require modification. Allowing for this effect becomes more important as the set torque is approached. the presence of light oil lubrication is the minimum standard recommended for consistency in controlled tightening of fasteners. nut or washer to make the strain visible and measurable as a permanent witness of proper bolt tensioning.. For other surface treatments or for specialised bolt assemblies involving higher preload requirement or special lock nut. For critical applications closer control or calibration checking is recommended. It is most widely used in tensioning bolts in structural steel work. the best accuracy and consistency of torque control tightening is obtained when rotation of the fastener is steadily maintained until the torque increases to the set level.F A S T E N E R S Tightening of Bolted Joints reuseability of the assembly. Because friction is the major unknown variable affecting the relationship between torque applied and tension induced. Difficulty maintaining steady movement up to the set torque is a drawback of some hydraulic tools used for large diameter fasteners. with a micrometer Fasteners your guarantee of quality industrial fasteners 23 . b) Direct Tension Indicators: These proprietary devices are also based on controlled strain. Bolt Length may be measured before and after tightening. c) Measurement of Bolt Extension: This is a time consuming but very accurate method. The writer conjectures that this variation is attributable to the change in plating practice from alkali-cyanide to acid chloride zinc plating electrolyte since this data was generated and perhaps more specifically to different lubricity of the brighteners used in these proprietary solutions.7 Phosphated and oiled 0. Greatest accuracy is achieved when the strain value is obtained from the load extension curve of the fastener being used.1 Zinc Plated – Degreased – Lightly oiled 0. A hollow bolt with a hydraulically actuated internal loading ram is available which makes removal as easy as installation. d) Pre-assembly Straining: The most common development of this method is the snug tightening of a normal nut on a bolt which has been heated to produce a calculated degree of thermal expansion.1 1. particularly if any parameters are known to have changed. As well as scatter in the torque-tension relationship for different assemblies from the same lot.Tightening of Bolted Joints F A S T E N E R S Table 17 Surface Condition Factor Galvanised – Degreased – Lightly oiled 2. Investigation of a 1991 complaint that assemblies torqued at this level were stripping found that the factor 0.9 Cadmium Plated – Degreased – Lightly oiled 1.7 is now appropriate.7* 0.0 0. The results of these tests are shown in Graphs 1-4.7 Standard finish plus heavy grease 0.7 * In previously published guidance for tightening by control of applied torque this factor shown as 1. but calculation based on Hooke’s Law gives good correlation when allowance is made for the respective lengths and cross-sectional areas of the plain and threaded portions of the bolt shank effectively in the grip. In recent tests of bright zinc plated parts the tension at a given torque was found to progressively reduce by 50% over five tightenings of an unlubricated assembly while a well lubricated assembly showed no reduction over five retightenings and only a 9% over twelve retightenings. It should be remembered also that such guidance is based on first tightening of single assemblies in isolation and that interactions in multifastener joints may result in changes to initial tension such that a detailed tightening sequence may need to be developed and followed for satisfactory service of the joint. Both the scatter and shift on retightening are minimised by good lubrication of threads and bearing face. in some joint configurations or by an electronic “sonar” type device from one end. The change emphasises that such published general information can only ever be regarded as a guide and verification of applicability for a specific application is advisable both initially and over time. retightening of the same bolt may give a different torque tension relationship. e) Strain Gauges: These are usually applied to the bolt Fasteners your guarantee of quality industrial fasteners 24 .9. The relaxation of tension due to bedding in and deflection of the mating threads is consistent for given assembly types and can be allowed for to maintain accuracy of the desired residual tension. Fasteners your guarantee of quality industrial fasteners 25 .F A S T E N E R S Tightening of Bolted Joints shank and calibrated in a load measuring machine. Their accuracy allows designs for bolts tensioned to their actual yield point and the implementation of this method has resulted in redesign with higher strength of standard metric nuts so that they In the most economic development of this method. (3) Combination Methods (4) Direct Tensioning Electronic sensors and microprocessors have been developed which simultaneously measure torque and/or angular rotation and/or instantaneous rate of change in these characteristics. uniform tensioning of many bolts. are unlikely to strip on bolts so tightened. Hand-held models are available with capacity for he size range common in automotive application but the methods are essentially confined to high volume application such as the simultaneous tightening of automotive engine head “bolts” (really cap screws). tension applied by a calibrated hydraulic jack attached to an extension of the bolt or stud thread is transferred to a normal nut after it is snugged up to the joint. This may be the most practicable method for bolts over M36/11/2" diameter and is particularly suitable for sealing of high pressure gasketed joints because manifolding of jacks enables simultaneous. 5 12 22 7.4 2788 30 16 22.9 5148 20 35.5 6.08 81.5 2.45 1900 17 Tensile Bolts 12 12.8 8048 24 51.Tightening of Bolted Joints F A S T E N E R S Table 18 Recommended Assembly Torques Bolt Type Diameter mm Bolt Tension Corresponding to 65% of Proof of Load kN lbf AS 1111 5 Blacks Property 6 2.1 1. Fasteners your guarantee of quality industrial fasteners 26 .3 Commercial Low 10 8.5 Class 4.6 8 5.9 468 Recommended Assembly Torque Nm ft.lbs 2.34 1200 8.6 11600 30 2.94 661 3. Refer to page 24 and table 17 for effects of various finishes.3 106 248 183 18412 491 362 36 120 26977 864 637 42 164 36869 1378 1016 48 215 48334 2064 1522 56 298 66993 3338 2462 64 393 88350 5030 3710 The torques listed are for plain finish (uncoated) fasteners as supplied.3 54 14. Fasteners your guarantee of quality industrial fasteners 27 . Refer to page 24 and Table 17 for effects of various finishes.F A S T E N E R Tightening of Bolted Joints S Table 19 Recommended Assembly Torques Bolt Type AS 2451 Blacks BSW Low Tensile Bolts (Formerly AS B100) Induced Bolt Preload Diameter or Tension and Thread Corresponding to 65% of Yield Load lbf Recommended Assembly Torque to Give Induced Preload Equal to 65% of Yield Load lbf 1/4 BSW 750 3 5/16 BSW 1230 6 3/8 BSW 1820 12 7/16 BSW 2480 19 1/2 BSW 3250 28 5/8 BSW 5300 55 3/4 BSW 7830 98 7/8 BSW 10200 150 1 BSW 13300 230 11/8 BSW 16700 320 11/4 BSW 21500 450 11/2 BSW 30800 780 The torques listed are for plain finish (uncoated) fasteners as supplied. Tightening of Bolted Joints F A S T E N E R Table 20 Recommended Assembly Torques Bolt Type Induced Bolt Preload Diameter or Tension and Thread Corresponding to 65% of Yield Load lbf Recommended Assembly Torque to Give Induced Preload Equal to 65% of Yield Load lbf 1/4 UNF 2020 8 5/16 UNF 3190 17 Unified High 3/8 UNF 4840 30 Tensile Bolts 7/16 UNF 6570 48 (Same as SAE 1/2 UNF 8840 74 J429 Grade 5) 5/8 UNF 14170 150 3/4 UNF 20610 260 AS 2465 Blacks Grade 5 7/8 UNF 28150 410 1 UNF 36660 610 1/4 UNC 1760 7 5/16 UNC 2890 15 3/8 UNC 4290 27 7/16 UNC 5880 43 1/2 UNC 7870 66 5/8 UNC 12480 130 3/4 UNC 18400 230 7/8 UNC 25550 370 1 UNC 33480 560 Fasteners your guarantee of quality industrial fasteners 28 S . F A S T E N E R Tightening of Bolted Joints S Table 21 Recommended Assembly Torques Bolt Type Induced Bolt Preload Diameter or Tension and Thread Corresponding to 65% of Yield Load lbf Recommended Assembly Torque to Give Induced Preload Equal to 65% of Yield Load lbf 1/4 UNF 2830 12 5/16 UNF 4520 23 3/8 UNF 6830 43 7/16 UNF 9230 67 (Same as SAE 1/2 UNF 12500 104 J429 Grade 8) 5/8 UNF 19960 207 3/4 UNF 29120 363 7/8 UNF 39720 577 1 UNF 51740 859 1/4 UNC 2470 10 5/16 UNC 4100 21 3/8 UNC 6050 38 7/16 UNC 8320 60 1/2 UNC 11050 92 5/8 UNC 17620 183 3/4 UNC 26070 325 7/8 UNC 36010 523 1 UNC 47200 785 AS 2465 Blacks Grade 8 Unified High Tensile Bolts Fasteners your guarantee of quality industrial fasteners 29 . Data for sizes above this is given for information only.2 13309 190 140 95.Tightening of Bolted Joints F A S T E N E R S Table 22 Recommended Assembly Torques Bolt Type Diameter mm Bolt Tension Corresponding to 65% of Proof Load kN lbf Recommended Assembly Torque Nm ft. The Blacks Fasteners stocked range extends to M24 but sizes 30.6 1709 9 7 Class 8. Refer to page 24 and Table 17 for effects of various finishes. Refer to page 24 and Table 17 for effects of various finishes.8 7149 77 57 16 59.50 18996 270 200 20 131. 36 Property Class 8.9 8 19. Fasteners your guarantee of quality industrial fasteners 30 . The torques listed are for plain finish (uncoated) fasteners as supplied.27 7030 63 46 Tensile Bolts 12 45.70 99073 3173 2342 The torques listed are for plain finish (uncoated) fasteners as supplied.76 4442 32 23 Precision High 10 31.67 1724 8 6 Blacks Property 6 10.50 10229 109 81 16 84.lbs AS 1110 5 7. Table 23 Recommended Assembly Torques Bolt Type Diameter mm Bolt Tension Corresponding to 65% of Proof Load kN lbf Recommended Assembly Torque Nm ft.4 1214 5 Blacks Property 6 7.95 29664 528 390 24 190.45 42815 914 675 30 302.lbs AS 1110 5 5.90 68095 1817 1341 36 440.6 274 20 4 21492 372 24 138 31024 640 472 30 219 49233 1314 969 36 319 71714 2297 1694 (42) 437 98242 3671 2707 (48) 573 128816 5500 4057 (56) 792 178049 8870 6542 (64) 1045 234925 13376 9866 AS 1110 covers sizes to M36 only.8 Bolts and Nuts are available from structural stocks.9 4923 44 32 Tensile Bolts 12 31.86 2441 13 10 Class 10.8 3102 22 16 Precision High 10 21.8 8 13. (3) Inspection Bolts and nuts that show on visual inspection any evidence of physical defects shall be removed and replaced by new ones. Tightening of the bolts shall proceed from the stiffest part of the joint toward the free edges.8TF/8.2) AS 4100 requires that the suitability of the device shall be demonstrated by testing at least three specimens for each diameter and grade in a calibration device capable of indicating bolt tension and proving that the device indicates a tension at least 105% of the specified minimum. a) Part Turn Tightening Method On assembly all bolts and nuts in the joint are first tightened to a snug tight condition. (1) Assembly Each bolt and nut shall be assembled with at least one washer and where only one washer is used it shall be placed under the rotating component. by ensuring that the correct part turn from the snug position can be measured or observed. the full effort of a man using a standard podger spanner or by a few impacts of an impact wrench. assembly and inspection of steel structures using metric high strength structural bolts and nuts to AS 1252 are covered in AS 4100 . Location marks are then established to mark the relative position of the bolt and nut. The bolts are then finally tightened by the amount shown in Table 24. For “direct tension indicator” tightening. The ASAA High Strength Structural Bolting Code which was withdrawn on 26/10/91.F A S T E N E R S Tightening of Structural Joints Bolting Categories 8. For “part turn” tightening. The requirements for bolting Categories 8. Tightening of bolts and nuts shall be in accordance with the manufacturer’s instructions and the following procedure2. The following methods shall be used to check that all bolts are fully tightened. Refer page 51. Under no circumstances shall bolts which have been fully tightened be reused in another joint or structure. (2) Methods of Tightening Tightening methods permitted can be either “part turn method” or use of “direct tension indicators” (CoronetR Load Indicators).8TF/8. Then the bolt and nut are tightened to provide the minimum tension specified in Table 25. Snug tight is defined as the tightness attained by b) Direct Tension Indicators1 b.1) This method of tightening can be carried out with CoronetR Load Indicators. fabrication. They may be retightened once in the same hole. The following are abstracts from AS 4100. On assembly all bolts and nuts in the joint are first tightened to the snug tight condition.8TB The design.8TB are in essence the same as those previously given in AS 1511 – 1984. by ensuring Fasteners your guarantee of quality industrial fasteners 31 . b.SAA Steel Structures Code which should be referred to for more detailed information. was not followed and direct tension indicators were not installed some method for subsequent checking of bolt tension is sometimes required by the inspection engineer. regardless of the component turned.Tightening of Structural Joints F A S T E N E R S Bolting Categories 8.8TF/8. for 2/3 turn or more. it is also not reliable for inspection of the correct tension in bolts either. one eighth of a turn (45°) over and nil under tolerance. these recommendations are set out on page 51. one twelfth of a turn (30°) over and nil under tolerance. method verification and application of match marking for later inspection. 5. 3. Therefore. but cannot be relied upon to distinguish bolts which although Fasteners your guarantee of quality industrial fasteners 32 . bolts which have been “snugged” only. The bolt tension achieved with the amount of nut rotation specified in Table 24 will be at least equal to the minimum bolt tension specified in Table 25. and was deleted from the SAA High Strength Bolting Code. The procedure given in the following is suitable for detecting gross under-tension. that the manufacturer’s specified tightening procedure has been followed and that the development of the minimum bolt tension is indicated by the tension indicating device. the required rotation should be determined by actual test in a suitable tension measuring device which simulates conditions of solidly fitted steel. 3. No research has been performed to establish the turn-of-nut procedure for bolt lengths exceeding 12 diameters. 2. In the event that Blacks Fasteners CoronetR Load Indicators have been used. Disposition of outer face of bolted parts (See notes 1. not least because few erectors purchased the equipment necessary to perform the procedure for calibration of the bolts/wrench combinations which are to be used in the structure. Nut rotation is the rotation relative to the bolt. a) Direct Tension Indicators Inspect according to the manufacturer’s recommendations. eg. 4. 2. Tolerance on rotation: for 1/2 turn or less. 4) Bolt Length (Underside of head to end of bolt) Both Faces One Face normal normal to axis to bolt axis and other sloped Both Faces sloped Up to and including 4 diameters 1/3 turn 1/2 turn 2/3 turn Over 4 diameters but not exceeding 8 diameters 1/2 turn 2/3 turn 5/6 turn Over 8 diameters but not exceeding 12 diameters (see note 5) 2/3 turn 5/6 turn 1 turn NOTES 1.8TB Table 24 AS 4100 . Nut rotations specified are only applicable to connections in which all material within the grip of bolt is steel. Logically. (4) Inspection of Bolt Tension using a Torque Wrench a) In the event that the specified procedure for part-turn tightening ie.1990 Nut Rotation from the Snug-Tight condition. Note that tightening by torque control was found to be reliable in practice. Samples. c) galling the time lapse between tensioning and inspection especially as regards corrosion which may have occurred. The inspection wrench may be either a hand-operated or adjustable power-operated wrench. NOTE: The principal factors which limit the reliability of the method are:a) the equivalence of thread and bearing face surface condition and lubrication of the calibration samples and job bolts. At least three bolts. It should be calibrated at least once per shift or more frequently if the need to closely simulate the conditions of the bolts in the structure so demands. Verifying proper snugging of all bolts in the joint. (This should be the time of first inspection . Applying match marks desirably permanent. or verifying about 1-2mm gap at Coronet load indicator. 4.F A S T E N E R S Tightening of Structural Joints Bolting Categories 8. Using the correct bolts and nuts (Blacks AS 1252 High Strength Structural) 2. Witnessing that the tooling available can easily achieve the required part-turn or crush the load indicator to the specified average gap.joint should be solid) 3.8TF/8. This is illustrated by fig. Adequately inspection with a torque wrench is virtually impossible because it is practically impossible to obtain samples for the calibration procedure which truly represent the bolts to be inspected. The point being that there is no “inspection torque” for each size of bolt! Each lot of bolts and each tool to be deployed must be individually calibrated at the time of tightening/inspection. It is emphasised that correct tensioning can only be assured by– 1. 15 which shows the torquetension calibration of three M24 galvanised bolt assemblies submitted from a site by a party required to apply torque-wrench inspection. The torque value determined during the calibration may not be transferred to another wrench.8TB tightened well beyond snug may not have been fully tensioned. desirably of the same size (minimum length may have to be selected to suit the calibration device) and conditions as those Fasteners your guarantee of quality industrial fasteners 33 . b) the occurrence of during tightening. The load indicator inherently provides a permanent witness of correct tensioning.1) Calibration Inspection Wrench. Bolt Tension Information for Setting Inspection Wrenches (4. Tightening of Structural Joints F A S T E N E R S Bolting Categories 8.8TF/8.8TB under inspection should be placed individually in a calibration device capable of indicating bolt tension. IMPORTANT: Without this calibrating device torque wrench inspection to the code is not possible! A hardened washer should be placed under the part turned. Each calibration specimen should be tensioned in the calibrating device by any convenient means to the minimum tension shown for that diameter in Table 25. The inspection wrench then should be applied to the tensioned bolt and the torque necessary to turn the nut or bolt head 5 degrees (approximately 25mm at 300mm radius) in the tensioning direction should be determined. The average torque measured in the tests of at least three bolts should be taken as the job inspection torque. (4.2) Inspection Bolts represented by the sample prescribed in Paragraph B2 which have been tensioned in the structure should be inspected by applying, in the tensioning direction, the inspection wrench and its job inspection torque to such proportion of the bolts in the structure as the supervising engineer prescribes. NOTE For guidance it is suggested that a suitable sample size would be 10 percent of the bolts but not less than two bolts in each connection are to be inspected. (4.3) Action Where no nut or bolt is turned by the job inspection torque, the connection should be accepted as properly tensioned. Where any nut or bolt head is turned by the application of the job inspection torque, this torque should then be applied to all other bolts in the connection and all bolts whose nut or head is turned by the job inspection torque should be tensioned and re-inspected. Alternatively, the fabricator or erector at is option, may retention all of the bolts in the connection and then resubmit the connection for inspection. Table 25 Bolt Tension Information for Setting Inspection Wrenches Bolt Tension Nominal bolt diameter Minimum kN Kips M16 95 21.3 ton f 9.5 M20 145 32.6 14.55 M24 210 48.6 21.7 M30 335 77.1 34.4 M36 490 112.9 50.3 Fasteners your guarantee of quality industrial fasteners 34 F A S T E N E R S Tightening of Structural Joints Bolting Categories 8.8TF/8.8TB Figure 15 This data, established on specimens returned from a site where inspection was required by the responsible Engineer, illustrates the difficulty of applying torque inspection to establish the correct tensioning of Bolting Categories 8.8TF/8.8TB connections. The plotted points show tension against the more consistent dynamic friction (nut in motion) torque rather than the torque to overcome static friction of a stationary nut as in the procedure in the Australian Structural Steel Code. Either way the calibration torque is determined on freshly tensioned assemblies which may or may not be what is to be inspected. The first point for the M24 x 100 removed from the structure is plotted twice as the wrench ran out of travel before reaching the 270 Nm set point the first time. Fasteners your guarantee of quality industrial fasteners 35 Structural Design Using Blacks Bolts F A S T E N E R S AS 1111 ISO metric hexagon commercial bolts and screws. AS 1112 ISO metric hexagon nuts, including thin nuts, slotted nuts and castle nuts. Acknowledgement: The following summary of design procedures to AS 4100 - 1990 is by Arun Syam and Arthur Firkins of AISC - Technical Services. The two basic types of metric bolt used in structural engineering in Australia are: • commercial bolts to AS 1111 (Strength Grade 4.6) AS 1252 High strength steel bolts with associated nuts and washers for structural engineering. AS 1275 Metric screw threads for fasteners. AS 1559 Fasteners – Bolts, nuts and washers for tower construction. • high strength structural bolts to AS 1252 (Strength Grade 8.8) References The design provisions for structural bolts are contained in Australian Standard 4100 - 1990: Steel Structures. This standard, in limit states design format, superseded AS 1250 - 1981 which was in a working stress format. AS 4100 - 1990 also incorporates the design and installation clauses of high strength bolts from AS 1511 1984: High Strength Bolting Code which it also superseded. [1] Design Capacity Tables for Structural Steel, 1st Edition, 1991. Australian Material Standards The relevant material standards referenced by AS 4100 – 1990 are the current editions: AS 1110 ISO metric hexagon precision bolts and screws. Further design guidance is available in the following publications by the Australian Institute of Steel Construction (AISC): [2] Bolting of Steel Structures, 3rd Edition, 1991. [3] Design of Structural Connections, 4th Edition, 1991. [4] Economical Structural Steelwork, 3rd Edition ,1991. Bolting Categories The strength of bolts is normally specified in terms of the tensile strength of the threaded fastener. As a consequence, grades of bolts are identified in the following manner: Fasteners your guarantee of quality industrial fasteners 36 F A S T E N E R Structural Design Using Blacks Bolts S commercial bolts of Strength Grade 4.6 conforming to AS 1111, tightened using a standard wrench to a 'snug-tight' condition. Grade X.Y (eg Grade 4.6 or Grade 8.8 where X – is one hundredth of the nominal strength (MPa) Y – is one tenth of the ratio between nominal yield stress and nominal tensile strength expressed as a percentage. A standard bolting category identification system has been adopted in AS 4100-1990. These are: • snug tightened (applies to commercial and high strength structural bolts) designated 4.6/S and 8.8/s respectively; • fully tensioned friction type (high strength structural bolts only) – designated 8.8/TF; • fully tensioned, bearing type (high strength structural bolts only) – designated 8.8/TB; The system of category designation identifies the bolt being used by using its strength grade designation (4.6 or 8.8) and identifies the installation procedure by a supplementary letter (S–snug; T–full tensioning). For 8.8/T categories, the type of joint is identified by an additional letter (F–friction-type joint; B–bearing type joint. Category 4.6/S refers to AS 4100-1990 describes 'snugtight' as "the tightness attained by a few impacts of an impact wrench or by the full effort of a person using a standard podger spanner". The aim of this installation is to achieve a level of tightness so that all plies in a joint are in full contact. It is a final mode of bolt tightening for 4.6/S and 8.8/S bolting categories, and the first step in full tensioning to 8.8/TF and 8.8/TB bolting categories – see below. Category 8.8/S refers to any bolt of Strength Grade 8.8 tightened to a 'snug-tight' condition as described above. These bolts are used as a higher grade commercial bolt to increase the capacity of certain connection types. Categories 8.8/TF and 8.8/TB (or 8.8/T when referring to both bolt types) refer specifically to high strength structural bolts of Strength Grade 8.8 conforming as AS 1252 fully tensioned in a controlled manner to the requirements of AS 41001990. The benefit of this bolting category is the increase in performance of the bolted joint in the serviceability limit state (ie limited joint slip), though for a penalty of installed cost – see Refs [2] and [4] above-mentioned. It is recommended that 8.8/TF category be used only in rigid joints where a no-slip joint is essential. See Table 26 for a summary of the above types and bolting categories. Fasteners your guarantee of quality industrial fasteners 37 fabrication. erection and modification of steel work in structures. the transfer of forces does not rely on shear and bearing but is dependant upon the frictional resistance of the mating surfaces (see Fig 17). In limit states design the following fundamental inequality must be satisfied. when the forces to be transferred are parallel to the bolt axis (see Fig 18). S* ≤ ø Ru where S* = design action effect (ie design shear load and/or design tension load) on the bolt Axial tension mode.8/TF. However. Also. These are: a) Shear/bearing mode where the forces are perpendicular to the bolt axis and are transferred by shear and bearing on the bolt and bearing on the connected plies (see Fig 16). The relevant bolting category is 8. Relevant bolting categories are 4.8/TB. For a description of 'limit states' reference should be made to Ref [1] above. 29 of AS 4100) These modes of force transfer may occur independently or with one another.4 of AS 4100-1990. This inequality states the design action effect (S*) must be less than or equal to the design Ru = nominal capacity of the bolt Fasteners your guarantee of quality industrial fasteners 38 . 8. there are three fundamental modes of force transfer to be considered. c) Minimum design actions on connections must be considered and these are set out in Clause 9. b) Friction mode. ø = capacity factor (from Table 28. Design Procedure to AS 4100-1990 AS 4100-1990 uses the limit states design method in the design.8/S and 8.Structural Design Using Blacks Bolts F A S T E N E R S Minimum Design Actions on Bolted Connections as AS 4100-1990 Modes of Force Transfer In the design of individual bolts in bolted structural connections. which is similar to the shear/bearing mode in that forces to be transferred are perpendicular to the bolt axis.1. bolts which are required to carry a design tensile force must be proportioned to resist any additional tensile force due to prying action. All bolting categories may apply to this.6/S. Bolt in Shear – Strength Limit State The following inequality must be satisfied for a bolt subjected to the design shear force (V*f ) for strength limit state: V*f ≤ ø Vf where ø = 0. 8.8/TB and 8.8/S. STRENGTH LIMIT STATE In AS 4100-1990 the strength limit state design provisions which apply for static load applications are found in Clause 9. in AS 4100-1990 the nominal shear capacity of a bolt (Vf) is given by: ii) serviceability limit state. Shear strengths obtained from research have shown that. For all other. Vf = nominal shear capacity of a bolt strength limit state.8/TF.4 of AS 41001990) where fuf = minimum tensile strength of the bolt (see Table 26) kr = reduction factor to account for the length of a bolted lap connection – Lj (see Table 29). The shear strength of a bolt is directly proportional to the shear area available.6/S. kr=1.8) for listings of bolt design shear capacity – strength limit state (øVfn and ø Vfx) – for the commonly used structural bolts.8 (Table 3.F A S T E N E R S Structural Design Using Blacks Bolts capacity of the bolt (øRu) for the design action considered. Fasteners your guarantee of quality industrial fasteners 39 . 8. They are: i) iii) fatigue limit state.2. The nominal capacity of the bolt is given in AS 4100-1990. This applies for all the commonly used bolting categories of 4. Vf = 0.3. It should be noted that the design action effect (S*) is calculated from an acceptable form of analysis using the factored limit state load as set out in AS 1170-1989: Minimum Design Loads on Structures (known as the SAA Loading Code).62fufkr(nnAc + nxAo) In bolting design there are three limit states that have to be considered.0 nn = number of shear planes with threads intercepting the shear plane Ac = minor (core) diameter area of the bolt as defined in AS 1275 nx = number of shear planes without threads intercepting the shear plane Ao = nominal plain shank area of the bolt See Table 27 (Grade 4. this being the core area (Ac) when considering the threaded part of the bolt or the shank area (Ao) when considering the unthreaded part. for bolts in shear. Therefore. the average shear strength of the bolt was 62% of the tensile strength (fuf).6) and Table 28 (Grade 8. 8 (Table 3. This considers that for a ply subject to a design bearing force (V*b) due to a bolt in shear. and øVfx = ø0.8) for the listings of bolt design tensions capacity – strength limit state (øNtf) – for the commonly used structural bolts. Vf.62fufAc for threads included in single shear plane. the following must be satisfied: V*b≤øVb where ø = 0. Ply in Bearing – Strength Limit State Design provisions for a ply loaded by a bolt in bearing are found in Clause 9. Bolts that are fully tensioned have. Ntf and ø are described above.Structural Design Using Blacks Bolts F A S T E N E R S Note: In Tables 27 and 28 – øVfn = ø0.4 of AS 41001990) Fasteners your guarantee of quality industrial fasteners 40 . for design purposes. tests have shown that the following elliptical interaction relationship applies: V*f/øVf)2 = (N*tf/øNtf)2 ≤ 1.4 of AS 4100-1990. where V*f.3.62fufAo for threads excluded from single shear plane.8) for a plot of the shear tension interaction relationship – strength limit state – for the commonly used structural bolts.6) and Table 28 (Grade 8. Bolt in Tension – Strength Limit State The following inequality must be satisfied for a bolt subjected to a design tension force (N*tf) for strength limit state: N*tf ≤ ø Ntf Bolt Subject to Combined Shear and Tension – Strength Limit State For bolts subject to simultaneous shear and tension forces.6) and Fig 20 (Grade 8. N*tf. no reduction in nominal tension capacity (see Ref [2] above.4 of AS 41001990) Ntf = nominal tension capacity of a bolt = Asfuf and As = tensile stress area of a bolt as specified in AS 1275 fuf = minimum tensile strength of the bolt (see Table 26) See Table 27 (Grade 4. See Fig 19 (Grade 4.0 where ø = 0.2.9 (Table 3. Bolt in Shear – Serviceability Limit State The following inequality must be satisfied for a bolt subjected only to a design shear force (V*sf) in the Fasteners your guarantee of quality industrial fasteners 41 . out-of-plane and also if a couple. bolt diameter and end distance. the design capacity for ply in bearing (øVb) exceeds both cases of threads included in and excluded from the shear plane (ie øVf as described above for the bolt in shear – strength limit state). Clause 9. for all reasonable combinations of ply thickness. shear or both act on the bolt group.3. For Grade 4.8/S. SERVICEABILITY LIMIT STATE The use of a bolted connection which does not slip or has limited slip under serviceability loads may be advisable under certain conditions. For further details see Ref [1]. as mentioned above.4 of AS 41001990 should be consulted for the design of actions on individual or critically loaded bolts.6 bolting category.2dftpfup and Vb = design bearing capacity due to plate tearout = aetpfup where df = diameter of the bolt tp = thickness of the ply fup = tensile strength of the ply ae = minimum distance from the edge of a hole to the edge of a ply. should be assessed separately.8/TB and 8. and 8. [2] and [3] above. In AS 4100-1990 the serviceability limit state design provisions are found in Clause 9. plus half the bolt diameter. Assessment of the Strength of a Bolt Group Depending on whether loading is in-plane. The edge of a ply can include the edge of an adjacent bolt hole. The strength limit state.8/TF bolting category. For the 8. measured in the direct of the component of a force.F A S T E N E R S Structural Design Using Blacks Bolts Vb = nominal bearing capacity of a ply Vb is calculated from the lesser of: Vb = design bearing capacity due to ply local bearing failure = 3. This type of connection is known as a friction-type joint and is identified as 8.8/TF bolting categories see Table 28 for listings of øVb for plate tearout and ply local bearing failure.3. 3. See Table 32 for the listings of bolt design shear capacity – serviceability limit state (øVsf) – for the commonly used structural bolts.85 for short slotted and oversize holes = 0.5.35 given for design purposes in AS 4100-1990 assumes faying surfaces of bare steel to bare steel – ie in the "asrolled condition". Bolt Subject to Combined Shear and Tension – Serviceability Limit State For bolts subject simultaneously to shear and tension forces. since the slip factor (µ) achieved in practice is directly related to the condition of the faying surfaces.1 of AS 41001990 (see Table 30) Bolt in Tension – Serviceability Limit State kh = factor for different hole types as specified in Clause 14.5.5 of AS 41001990) Vsf = nominal shear capacity of bolt.35 for clean as-rolled surfaces or determined by testing in accordance with Appendix J of AS 4100-1990 nei = number interfaces of Often steel members are painted or galvanised and it is important to know what influence this may have on the slip factor. The slip factor 0.Structural Design Using Blacks Bolts plane of the interfaces serviceability limit state: F A S T E N E R S for V*sf ≤ ø Vsf where ø = 0. = 1. for a friction-type connection = µneiNtikh where µ = slip factor = 0.2 of AS 4100-1990 Not relevant in this limit state.0 for standard holes = 0. the following linear interaction relationship applies: Fasteners your guarantee of quality industrial fasteners 42 . Typical values of the slip factor for various surface preparations are given in Table 31.7 (Clause 3.70 for long slotted holes The condition of the faying (or contact) surfaces is of prime importance. Tension loadings for serviceability limit state are only considered when interacting with shear loads at serviceability limit state – see below.2.5. effective Nti = minimum bolt tension at installation as specified in Clause 15. 8/TF and 8.1 of AS 41001990 (see Table 30) See Fig 21 for a plot of the shear tension interaction relationship – serviceability limit state – for the commonly used structural bolts. a detail category is assigned to bolted connections subject to normal stress (tension) and shear stress. tensile stress being calculated on the tensile stress area.6/S and 8. For the tension loads: N*tf = design tension force on the bolt Ntf = nominal tension capacity of the bolt = Nti = the minimum bolt tension at installation as specified in Clause 15.F A S T E N E R S Structural Design Using Blacks Bolts corresponds to the fatigue strength at 2 x 106 cycles on the appropriate S-N curves. Reference should be made to AS 4100 Supplement 1-1990: Steel Structures – Commentary. For bolts. This detail category is a number which Detail category 36 bolts in tension. Fasteners your guarantee of quality industrial fasteners 43 . In summary. As no slip occurs with category 8. Vsf and ø are described above. Ac.5.2.8/S bolting categories. the uncorrected fatigue strength (ff) for detail category 100 subject to nsc (number of stress cycles) of loading or stress is given by f 5f = (105 x 2 x 106)/nsc when nsc ≤ 108 This relationship is shown in Fig 22. (V*sf /øVsf)2 + (N*tf /øNtf)2 ≤ 1.8/TB bolting category. For bolts subject to shear force. namely Detail category 100 bolts in shear. Additional tension forces due to prying must be taken into account.8/TB bolting category where shear stress must be calculated on the core areas. 8. a different S-N curve being used for each detail category. FATIGUE LIMIT STATE It is not possible to review here the fatigue provisions of AS 4100-1990 Section 11. AS 4100-1990 does contain design fatigue provisions for 8. Only 8. Bolt in Shear – Fatigue Limit State For shear stress. the fatigue provisions of AS 4100-1990 (Section 11) gives no guidance for 4. no separate design for fatigue of the bolts is required.0 where V*sf. AS 4100-1990 provides two detail categories. As.8/TB are recommended.8/TF. Listings of minimum pitch between centres of fastener holes. JHA.8/TB are recommended.6/S and 8.Structural Design Using Blacks Bolts Bolt in Tension – Fatigue Limit State For normal stress (tension). Kulak. minimum edge distance. 2nd Edition. bolting categories 4.8/S are not recommended and 8.2. maximum pitch.8/TF and 8. Design Detail for Bolts Clause 9. John Wiley 1987. AS 4100-1990 does not contain design provisions for these bolts subject to combined shear and tension under fatigue conditions. and minimum edge distance from the centre of a fastener to the edge of a plate or the flange of rolled section is given in Table 33(a) and 33(b) respectively.3. and maximum edge distance. Note that minimum edge distance criteria must also be observed from Clause 9. Bolt Subject to Combined Shear and Tension – Fatigue Limit State F A S T E N E R The following reference contains a review of research on fatigue in bolted connections: Guide to Design Criteria for Bolted and Riveted Joints. JW and Struik. the uncorrected fatigue strength (ff) for detail category 36 subject to nsc cycles of loading or stress is given by f 3f = (363 x 2 106)/nsc when nsc ≤ 5 x 106 5 f f = (365 x 108)/nsc when 5 x 106 < nsc ≤108 This relationship is shown in Fig 22. For bolts subject to tension force.6 of AS 4100-1990 gives the provisions for design details of bolts. This includes minimum pitch. Fasteners your guarantee of quality industrial fasteners 44 S . GL Fisher.4 of AS 41001990. 8 830 660 High Strength Structural AS 1252 Bolts used are Snug tightened. 8. Cost of tensioning is an important consideration in the use of these bolting categories.6 400 240 Commercial 8. Least costly and most commonly available 4. it can also be used in a snug tight condition. Fasteners your guarantee of quality industrial fasteners 45 .6/S 4. 8.8/TF 8.8 830 660 High Strength Structural Bolt – Fully Tensioned Bearing Type Joint 8.8 830 660 High Strength Structural Bolt – Fully Tensioned Friction Type Joint AS 1252 In both applications bolts are fully Tensioned to the requirements of AS4100. The high strength structural has a large bolt head and nut because it is designed to withstand full tensioning (see 8. However.8T category description).6 Grade bolt.F A S T E N E R Blacks Structural Bolts S Table 26 Bolt Types and Bolting Categories Details of bolt used Minimum Minimum Bolting Tensile Yield Category Strength Strength Strength Grade (MPa) (MPa) Name Australian Method of Standard Tensioning Remarks 4.8/TB AS 1111 Use Snug tightened.8/T 8.8/S 8. the design capacity for a ply in bearing (ØVb) exceeds both ØVfn and ØVfx.2 28.6 129 79 89 100 103 118 133 129 148 166 155 177 199 142 189 236 M24 234 133 186 170 227 283 M30 373 214 291 tp = 6 tp = 8 tp = 10 tp = 12 35 40 45 35 40 45 35 40 45 35 40 45 6 8 10 213 283 354 ae < aemin = 1.1 22. For all reasonable combinations of ply thickness.6 39.8X/S fup = 410 MPa fup=410MPa Fasteners your guarantee of quality industrial fasteners 46 .8 ø = 0.0 15.6X/S NOTE 1.7 113 151 189 M20 163 92.3 M36 261 151 89.Blacks Structural Bolts F A S T E N E R S Table 27 Design Shear and Tension Capacities – Strength Limit State Commercial Bolts 4.8/S 8.4 44. bolt diameter and end distance. Table 28 Design Shear and Tension Capacities – Strength Limit State High Strength Structural Bolts 8.8 ø = 0.8/TF Bolting Categories Grade 8.9 M20 78.7 140 202 ø = 0.6 62.6N/S 4.8N/S 8.9 ø = 0.8 ø = 0. Bearing/Plate Tearout Design Capacity.5 df ø = 0.8 (fuf = 400 MPa) Single Shear Bolt Axial Threads Threads Size Tension included excluded Plate Tearout Bearing øVb for tp & ae of: øVb for tpf in Shear Plane from Shear Plane øNtf øVfn øVfx kN kN kN M16 104 59.3 M24 113 M30 180 103 64.6/S Bolting Category Grade 4.6 (fuf = 400 MPa) Shear Values (Single Shear) Bolt Size Axial Tension ø Ntf Threads included in Shear Plane – N ø Vfn Threads excluded from Shear Plane – X ø Vfx kN kN kN M12 27.8/TB 8.9 8.3 82.8 4.4 M16 50. 53 Painted Red oxide zinc chromate Inorganic zinc silicate 0.8 16.7) Bolt Size Bolt Tension at Installation Grade 8.075 – Lj/4000 0.8 Design Capacity in Shear (øVsf) for kh = 1 kh = 0.1 69.48 0.75 Lj = length of a bolted lap splice connection.5 30.50 Hot-dip Galvanised Clean as-galvanised Lightly abrasive blasted 0.11 0.0 M30 335 82. Table 31 Summary of Slip Factors Surface Treatment Average Slip Factor Uncoated Clean as-rolled Flame cleaned Abrasive blasted 0.2 24.F A S T E N E R Blacks Structural Bolts S Table 29 Reduction factor for lap connections (kr) Length Lj < 300 300 ≤ Lj ≤ 1300 Lj > 1300 kr 1.0 1.9 M24 210 51.35 0.3 M20 145 35.5 Fasteners your guarantee of quality industrial fasteners 47 .30-0.18 0. Table 30 Minimum bolt tension at installation Nominal Diameter of Bolt Minimum Bolt Tension kN M16 95 M20 145 M24 210 M30 335 M36 490 NOTE: The minimum bolt tensions given in this Table are approximately equivalent to the minimum proof loads given in AS 1252.5 43.7 36.40 Table 32 Design Shear Capacity – Serviceability Limit State High Strength Structural Bolts 8.35 nei = 1 ø = 0.8/TF Bolting Category (µ = 0.8 57.3 19.85 kh = 0.7 kN kN kN kN M16 95 23. 16 17.00 35. Thickness m Max.5 20.00 21. Min.00 45.8 Thread ISO Metric Coarse Pitch Series Dimensions to AS 1252 Table 34 Bolt Dimensions Pitch Size of Body Dia.3.84 29.65 50 49.3.80 37. Width Across Flats s Max.75 9.3 20.44 23.30 27 26. Fasteners your guarantee of quality industrial fasteners 48 . Max.2.0 All dimensions in millimetres.1 16.3 30.90 12.25 27 26.45 60 58.Blacks Structural Bolts F A S T E N E R Table 33b Minimum Edge Distance (Clause 9.3 24.4 of AS 4100-1990 NOTE: The edge distance may also be affected by Clause 9. Width Across Flats s Min.6 36.00 25.55 21.90 14.70 15. Thread D D1 Max. Min.00 35. Hand Flame Machine Rolled Edge Cut Edge Flame Cut of a Rolled Sawn or Section Planed Edge (mm) (mm) (mm) Bolt size Minimum distance between centres of fastener holes mm M12 30 M12 21 18 15 M16 40 M16 28 24 20 M20 50 M20 35 30 25 M24 60 M24 42 36 30 75 M30 53 45 38 90 M36 63 54 45 M30 M36 S NOTE: The edge distance may also be affected by Clause 9.56 10.37 19.0 M24 3.0 37.20 15.0 M20 2.0 24. Min.0 16.0 M30 3.10 41 40.16 41 40.10 32 31.6.16 29. M16 2. Max.2. Nut Dimensions Width Head Corners Thickness e k Across Min.2 of AS 4100-1990) Table 33a Minimum Pitch between Centres of Fastener Holes (Clause 9.80 66.0 M36 4.16 32 31.5 30.1 of AS 41001990) Bolt Size Sheared or Rolled Plate.16 50 49.00 55.75 17. Min.00 31.03 13.00 60 58.4 of AS 4100-1990 Blacks High Strength Structural Bolts Property Class 8.84 23.6.84 19. 4 4.0 72.76 6.0 48. M16 D1 Mean Thickness A All dimensions in millimetres.4 M30 33. Min.45 4.0 44.52 26.52 22.0 50. Thickness A Max.4 4.1 M24 26.0 32.60 34 All dimensions in millimetres.43 18.0 70.0 34.60 3.35 M20 22.1 4.43 18.0 39. Fasteners your guarantee of quality industrial fasteners 49 .F A S T E N E R Blacks High Strength Structural Bolts (Flat Round Washers) S Standard Thread Length for Bolts Nominal Length of Bolt I Nominal Length of Thread b Up to and including 125mm 2D + 6mm Over 125 up to and including 200mm 2D + 12mm Over 200mm 2D + 25mm Table 35 Dimensions of Flat Round Structural Washers Nominal Diameter of Bolt Inside Diameter D1 Max. Min.52 26.60 3.75 4.76 6.60 3.4 4. Outside Diameter D2 Max.52 22.0 38.60 3.62 39.0 58.4 M36 39.1 M20 22. Width Across Flats D2 Nominal 5° Taper 8° Taper 18.76 6.1 4.62 33.10 4. Blacks High Strength Structural Bolts (Square Taper Washers) Table 36 Dimensions of Square Taper Washers Inside Diameter Min.0 60.35 M24 26. Min.0 37. M16 18.35 Nominal Diameter of Bolt Max.0 31. MOST IMPORTANT: A nut should not be slackened after fully tightening with a Load Indicator. The nut is then tightened until the protrusions are flattened and the gap reduced to that shown in Table 37. The Load Indicators are special hardened washers carrying 4 to 7 protrusions. Fasteners your guarantee of quality industrial fasteners 50 . In applications where it is necessary to rotate the bolt head rather than the nut in tightening. First stage involves a preliminary tightening to a "snug tight" condition using a podger spanner or pneumatic impact wrench.40mm or less and this can be checked with a feeler gauge. They can be supplied with galvanised coating for good corrosion resistance. Coronet Load indicators are designed for use with Blacks high strength structural bolts and they provide a simple and accurate aid to tightening and inspection. In tightening with Load Indicators it is still required that this tightening be carried out in two stages. fit a new Load Indicator for the second tightening. On large joints take a second run to ensure that all the bolts are "snug tight". depending on bolt diameter (Figure 27) and these are assembled with the protrusions bearing against the under side of the bolt head. leaving a gap. If this is necessary. Carry out final tightening by reducing gap between bolt head and load indicator to 0.Coronet Load Indicators F A S T E N E R S For direct tension indication tightening of Blacks Fasteners High Strength Structural Bolts AS 1252. The object of the preliminary tightening is to draw the mating surfaces into effective contact. the Coronet Load Indicator can be fitted under the nut using an extra hard round washer under the nut and protrusions bear against this washer (Figure 29). The induced bolt tension at this average gap will be not less than the minimum specified tension in Table 38. 25mm Under nut with hard flat washer.84 4.26 220 M30 59.59 30. black and all flat washer coatings 0.00 37.4mm All plating except galvanised bolts 0.25mm Table 38 Load indicator gaps to give required minimum shank tension Nominal Bolt Diameter Outside Diameter D2 Inside Diameter D1 Thickness A Max.26 515 Fasteners your guarantee of quality industrial fasteners 51 . Minimum Bolt Tension kN M16 35.50 4.26 150 M24 50.67 20.F A S T E N E R Coronet Load Indicators S For direct-tension indication tightening of Blacks Fasteners High Strength Structural Bolts AS 1252.26 100 M20 41.70 4.4mm Galvanised bolts 0. Table 37 Load indicator gaps to give required minimum shank tension Load Indicator Fitting AS 4100 (1511) Under bolt head black finish bolts 0.45 16.69 24.84 4.26 350 M36 80.84 4. 211 .3690 9/16 .5000 .625 .163 .974 .488 21/4 2.500 1.272 .125 1.3125 . UNC.812 .291 . Min.348 .323 .798 .2.455 1.243 .631 .245 7/16 .6250 .469 . Max.949 21/2 11/4 12 7 1.3065 1/2 . Head Across Thread thickness Corners Length B C T Max.175 .812 .551 .226 .938 .1 Finished Hexagon Bolts AS 2465 Table 39 Size Threads per inch UNF UNC Body Diameter Width Across Flats A Nom.750 .562 .875 .563 .516 2" 1 12 8 1.591 1.500 1.371 .378 1.312 1.650 1 7/16 20 14 .4305 5/8 .531 1.125 1.438 .722 11/8 1/2 20 13 .598 31/4 Fasteners your guarantee of quality industrial fasteners 52 .100 .922 .239 17/8 1.577 7/8 3/8 24 16 . UNF.299 13/4 9/16 5/8 3/4 18 18 16 12 11 10 7/8 14 9 .150 .902 2.813 .612 .688 1.165 23/4 11/2 12 6 1.718 .250 1.195 .866 15/16 1.Unified High Tensile Hexagon Bolts F A S T E N E R S Threads.4375 . 1/4 28 20 .3750 .4930 3/4 .403 .083 11/2 .505 3/4 5/16 24 18 .250 .938 13/8 . Min.750 .732 21/4 11/8 12 7 1.489 .741 11/8 1.6170 15/16 .114 111/16 1.000 . Min.500 . Class 2A Dimensions to ANSI/ASME B18.250 2.627 .5545 13/16 .483 . Max.866 11/4 . Min.749 2.302 .990 11/2 1.736 .285 .5625 .875 1.428 .658 1. Max. 438 .015 7/16 20 14 .428 . Fasteners your guarantee of quality industrial fasteners 53 .505 . 1/4 28 20 .557 .500 .025 . Max.211 .025 .015 NOTE: Set Screws shall be threaded to within 21/2 pitches of the underside of the head. UNC. Max. Min.551 .577 .489 .195 .291 .226 .625 . UNF.163 .488 .243 . Min. Dimensions to ANSI/ASME B18.562 .F A S T E N E R Unified Hexagon Head Set Screws – High Tensile S Threads. Max.1 AS 2465 Table 40 Size Threads per inch UNF UNC Head Across Flats A Head Depth B Head Radius Across Corners Under Head C R Max.698 .150 .025 .628 . Min.025 .015 3/8 24 16 .722 .612 .272 . Min.2.015 5/16 24 18 .650 . 28 33. Table 42 Standard thread lengths for bolts.65 3.58 6. Screws are threaded to head.0 17.35 Min.0 23.0 23.78 3.75 12.79 M6 1.38 M10 1.0 9.53 M24 3. Max.15 14.72 12. M5 0.77 M12 1.0 11.8 5. Min.0 7.78 39.0 5.5 20.15 3.78 13.73 6.67 30.0 6.03 M16 2.78 16.0 16.73 24. Max.8 Fasteners your guarantee of quality industrial fasteners 54 .82 10.8 and 10.0 12.67 12.45 5.98 All dimensions in millimetres.73 18.32 20. 8.85 11.25 8.0 19.0 9.73 7.0 24.9 are dimensionally the same as Property Class 8.38 15.0 35.18 9.22 17.67 10.0 7.78 4.06 M8 1.0 29.0 15.22 14.75 M20 2. Min.5 10. Min.68 7.0 4.82 26. Nominal Length of Bolt I Minimum Length of Thread b Up to and including 125mm 2D + 6mm Over 125 up to and including 200mm 2D + 12mm Over 200mm 2D + 25mm Where D = Nominal diameter in millimetres Note: Property Classes 5.Metric Hexagon Precision Bolts & Set Screws F A S T E N E R S Table 41 Size Pitch of Thread D Body Diameter Ds Width Across Flats s Head Thickness k Across Corners e Max.82 8.67 36.0 15.73 5. 57 7. Min.38 3.16 13.55 M30 3.0 24.16 46.00 35.30 24.0 23.25 8. Max.45 60.0 17.00 19.16 10. 5.62 10.90 14.25 26.84 19.60 32.0 29.0 16.85 5.80 23.0 45.70 11.16 36.79 All dimensions in millimetres.58 9.55 21.89 M8 1.17 M20 2. M6 1.75 17. Property Class 8.F A S T E N E R Metric Hexagon Commercial Bolts & Set Screws S Thread ISO Metric Coarse Pitch Series.57 6.05 19.95 17.59 M12 1.64 4. Max.0 12.0 9.92 14.5 20. Thread Class 8g.75 12.42 13.42 16.95 M24 3.0 15. Screws are threaded to head Nominal Length of Bolt I Minimum Length of Thread b Up to and including 125mm 2D + 6 Over 125mm up to and including 200mm 2D + 12 Over 200mm 2D + 25 Where D = Nominal diameter in millimetres For nut dimensions refer to page 14 Fasteners your guarantee of quality industrial fasteners 55 .85 M36 4. Min.00 55.0 53.58 7.48 Width Across Flats s Head Thickness k Across Corners e Min.0 37.70 15.0 6.84 29.65 50.40 11.5 10. Table 44 Standard thread lengths for bolts.20 M10 1.00 15.57 5.8 Dimensions to AS 1111 Table 43 Size Pitch Body Diameter of (On Bolts) Thread Ds D Max.75 9.52 10.30 18.0 35.10 39.85 M16 2.68 4.16 30. Min.5 30.95 7.84 23. 623 .790 1.600 .021 3/8 16 .50 .031 .706 .820 .333 .468 .515 .280 .17 .046 .800 .985 . Max.175 .021 1/2 12 .583 1.447 .021 5/8 11 .82 .405 .250 .695 .046 .530 .915 1.71 .021 7/16 14 .062 .666 1.186 .69 . Min.166 .312 .530 .031 .040 1.270 .036 7/8 9 .342 .062 .445 .031 .417 1. Max.031 .585 .665 1.500 1.010 .Hexagon Head Bolts F A S T E N E R Threads BSW Free Class Dimensions to AS 2451 Table 45 Size Threads Body Head per Diameter Across Flats inch s Max. Min. Max.300 1.710 .95 .031 .036 3/4 10 .052 Fasteners your guarantee of quality industrial fasteners 56 S .480 1.292 .39 .61 .021 5/16 18 .208 .450 .270 .363 .052 1 8 1.435 . Min.51 .228 .200 1. 1/4 20 .525 . Head Depth k Across Radius Corners Under Head e R Max. 61 .F A S T E N E R Hexagon Head Set Screws S Threads BSW Free Class Dimensions to AS 2451 Table 46 Size Threads per inch Head Across Flats Head Depth s k Max.583 1. Head Across Corners e Radius Under Head Min.706 .447 .417 1.175 .695 .062 .300 1.052 NOTE: Set screws shall be threaded to within 21/2 pitches of the underside of the head. Min.021 5/16 18 . 1/4 20 .186 .031 .623 .333 . Fasteners your guarantee of quality industrial fasteners 57 .046 .031 .228 .363 .95 .166 .021 5/8 11 1.312 . Max.208 .021 7/16 14 .530 .445 .600 .985 .480 1.69 .292 .031 .046 .052 1 8 1.270 .270 .435 . Min.585 .515 .820 .525 .710 .500 1. Min.021 1/2 12 .71 .010 .666 1.450 .200 1.036 3/4 10 1.50 . Max.39 .800 .021 3/8 16 .250 .036 7/8 9 1.17 .031 .062 .031 .51 .82 . 6 3.0 34.25 7.0 13.52 3.0 For nut dimensions refer to page 14 Standard Thread Length for Bolts Nominal Length of Bolt / Minimum Length of Thread b M5 M6 M8 M10 M12 M16 M20 M24 Up to and including 125mm 16 18 22 26 30 38 46 54 Over 125 up to and including 200mm 22 24 28 32 36 44 52 60 Over 200mm – – 41 45 49 57 65 73 Maximum thread length shall not exceed 80mm Mechanical Properties: Tensile Strength = 400 MPa (N/mm2) minimum = 58.84 19.0 27.58 9.000 lbf/in2 minimum = 25. Pitch Diameter of Body Size of Reduced Full and Thread Body Body Thread D1 D2 Dia.1 20.Metric Cup Head Square Neck Bolts F A S T E N E R S Threads ISO Metric Coarse Pitch Series Dimensions to AS 1390 Table 47 Metric Series Cup Square Bolts Nom. Min.42 10.0 22.5 12. Max.70 15.70 11. Length of Square Neck f Min. Max.9 8.30 16.9 10.42 5.7 6. Min.58 7.16 10.2 5.5 18.5 21.9 4.4 10.2 6.8 6.70 11. Head Diameter Head Thickness D3 k Min.58 9.48 5.48 5.6 12. Max. Min. Across Flats of Square Neck V Min.0 16.75 10.58 7.0 18.8 4.0 M12 1.0 M10 1.4 3.6 3.0 8.0 M8 1.30 8.0 5.0 36.8 5.9 8.30 12.70 15.84 19.8 6.5 16.50 8.42 8. Max.0 M16 2.16 20.8 4. M6 1.8 10.0 M20 2.0 43.0 45.30 6.0 14.9 10.42 4.4 8.9 tonf/in2 minimum Fasteners your guarantee of quality industrial fasteners 58 . Max.8 5.52 6.0 25. 733 .094 .125 .F A S T E N E R S Cup Head Square Neck Bolts Threads BSW Free Class Dimensions to AS B108 Table 48 Size Threads per inch Head Diameter A Head Thicknes B Depth of Square C Width of Square W Max.125 .873 .095 .250 .014 .183 1/4 20 .388 .673 .368 7/16 14 1.156 .238 .451 .187 .156 . Max.532 .492 For nut dimensions refer to page 14 Fasteners your guarantee of quality industrial fasteners 59 .281 . Min.219 .307 3/8 16 .245 5/16 18 .592 . 3/16 24 .219 .515 .125 .431 1/2 12 1. Min.188 .113 .093 .813 .323 .250 .156 .260 .391 .207 .218 . Min.176 .954 .270 . Min.145 .197 . Max.451 .250 . Max.155 1.187 . 000 lbf/in2 minimum = 25.Coach Screws – Hexagon Head Metric Series F A S T E N E R Dimensions to AS 1393 Table 49 Metric Series Coach Screws Nom.88 8.16 26.10 15.89 4.55 8. Min.42 13.2 Mechanical Properties Tensile Strength = 400MPa (N/mm2) minimum = 58.0 16.48 20. 6 2.48 5. Root Dia. Size Pitch of Thread Body Diameter D mm Max.5 6. Min.0 8.7 11.84 19.5 16 5.30 24.58 7.9 tonf/in2 minimum Fasteners your guarantee of quality industrial fasteners 60 S .6 5. Min.0 12.42 17.72 7.0 10 3. Max.88 5.45 7.0 23.20 5.70 11.38 3.3 7.2 12 4.3 20 5.12 5.0 16.30 19.57 14.16 32.52 10.4 3.7 8 3.57 18.64 10.0 9.90 12.6 14.0 12.45 6.0 20. Min. Width Width Head Across Across Thickness Flats Corners s e k Max.70 11.0 29.55 12.45 9.58 9.55 7.16 30. Min.0 18.17 10.62 4.5 10.95 13. of Thread ds Max.0 6. 120 . of Pegs C Max.697 . Min. Pitch Dia. Head Depth B Max. Fasteners your guarantee of quality industrial fasteners 61 .490 .047 . Min. Length of Peg D Max.077 1.217 24° 20° 13° Mechanical Properties Tensile Strength = 28 tonf/in2.829 . Min. Min.F A S T E N E R Elevator Bolts Four Peg S Threads BSW Free Class Table 51 Size Threads per Inch Head Diameter A Max. 1/4 20 .667 .136 17° 5/16 18 .174 22° 18° 3/8 16 1.237 .760 .156 . Angle Under Head E Max.615 .174 .100 .140 . Supplied with nut and washer.859 .635 . Min.194 .194 .510 .740 .160 . Max.5 65.20 25.8 27.0 10.00 29.30 M24 3.50 16.56 M42 4.5 85. Max.2 15.6 3.56 45.0 41.0 29.40 8.50 M10 1.10 65.0 36.0 17.79 31.75 14.00 50.30 M33 3.00 45.8 37.95 18. Thickness Standard Nut Thin Nut m t Min.86 52.55 21.10 71.73 17.5 30.0 55.8 33.37 7.03 10.04 6.6 20.0 5.0 75.10 – – All dimensions in millimetres.Metric Hexagon Nuts F A S T E N E R Threads ISO Metric Coarse Pitch Series.50 M30 3.80 60.60 24.20 4.00 16.40 21. Class 6H.05 5.90 3.75 18.96 M36 4.30 34.65 33.0 11.30 M8 1.75 M6 1.73 14.8 44.85 25.40 31.0 40.16 32.70 M12 1.4 13.50 20.77 8.2 24.67 26.80 10. Table 52 Size Pitch of Thread Width Across Flats s Max.20 23.90 12.0 53.0 35. Min.0 2.30 18.70 27.80 104.0 50.37 28.0 15.0 49.00 55.0 17.70 4.0 24.6 9. Min.20 28.8 4.02 M20 2.73 20.78 11.79 4.5 50.60 38.50 16.0 63.70 M27 3.00 39.20 14.80 93.0 23.20 – – M64 6.0 73.80 14.5 46.25 13.0 95. Fasteners your guarantee of quality industrial fasteners 62 S .8 8.0 12.76 M39 4.0 82.4 22.8 18.10 9.10 82.0 58.80 6.2 6.78 8.36 M48 5.0 7.40 19. Width Across Corners e Max. Property Class 5 M20-M64 incl.0 9.96 M56 5.0 92. These nuts are stocked in Property Class 8 M5 to M16 incl.0 60.38 6.80 23.44 4. M5 0.84 M16 2.0 45.40 3.80 22. 312 .78 1.19 1.750 .920 .565 1.395 .562 . Max.860 1.37 1.728 . Max.98 1.450 1.750 1.833 11/2 6 2.82 .010 .250 .090 3.64 1.583 11/8 7 1.875 .410 .760 2.300 .37 .330 .319 .060 1.330 1.250 1.51 .15 1.180 5/16 18 .525 .490 .365 2.210 .10 2.125 2.690 1.480 1.005 2.125 .93 1.300 1.065 1.375 . Nuts m Thickness Lock Nut t Min.260 .61 .435 . Min.06 .250 .332 .550 .166 21/4 4 3.980 .695 .375 3/4 10 1.69 .700 3.437 .5 2.810 .530 .200 3/8 16 .875 1.205 1.687 .50 .175 2.275 .083 4.815 2. 1/4 20 .220 2.445 .71 .F A S T E N E R Hexagon Nuts & Hexagon Lock Nuts S Threads BSW Dimensions to AS 2451* up to 15/8" *Hexagon nuts only Table 53 Size Threads per inch Width Across Flats s Width Across Corners e Max.600 .710 .323 5/8 11 1.157 Max.410 2.985 1.580 2.520 2.916 15/8 5 2.250 7/16 14 .270 1.490 4. 3/16 24 .935 .416 2 Fasteners your guarantee of quality industrial fasteners 63 .467 .000 13/4 5 2.800 .580 1.500 .500 1.458 7/8 9 1.200 1.175 1.820 .250 21/2 4 3.890 .17 .640 1.720 .455 1.585 .167 .550 3.050 2.160 1.630 .060 1.666 11/4 7 1.200 .515 .810 .750 13/8 6 2.625 1.290 9/16 12 .150 3.220 .324 .815 1.375 .430 1.56 1. Min.185 .270 .000 .900 1.670 1.500 1 8 1.602 .600 1.39 .95 .265 1/2 12 . 010 .83 3.500 1.650 . Max.000 ASTM: A563 Grade A UNF Nuts to other specifications (eg SAE Grade 8) or SAE Grade 5 in.768 .324 .861 1.363 7.488 . Min. Jam 1/4 20 28 UNC UNF .301 5.438 .938 .519 28.337 .125 1.535 .887 UNF .000 ASTM: A563 Grade B UNF 109.831 .212 .302 3.000 3/4 – 11/2" can Fasteners your guarantee of quality industrial fasteners 64 .240 .510 .675 .68 5/8 11 18 UNC UNF .450 1.180 1.387 .688 .312 1.84 1.2 AS 2465 Table 54 Threads per Inch Dia. Std.260 .577 . Min.724 .2.575 .557 .505 .496 .446 .083 1.736 .447 .226 .750 .500 .473 .982 . Across Across Thickness Flats Corners Approx Wt.448 . F G Standard H Jam Nut T lbs per 100 Max.767 7.227 . Min.653 .051 .562 .75 2.05 7/16 14 20 UNC UNF .163 . be quoted against enquiries.62 9/16 12 18 UNC UNF . Max.385 .776 UNF .299 1.323 .60 1.195 .753 .628 .10 3/8 16 24 UNC UNF .150 5/16 18 24 UNC UNF .866 .617 .93 3/4 10 16 UNC 1.210 1.86 1/2 13 20 UNC UNF .000 SAE Grade 2 UNC 90.365 .516 1.732 1. 90.6 .0 1 8 12 UNC 1.458 19. Class 2B Dimensions to ANSI/ASME B18. Max.33 4.269 1.875 . Min.Unified Hexagon Nuts & Hexagon Lock Nuts F A S T E N E R S Threads UNC.258 .551 .3 17.665 UNF .922 1.320 .840 .427 .240 2.515 .794 .273 .9 7/8 9 14 UNC 1.489 .70 Table 55 Mechanical Properties (Hexgaon Nuts) Size Range Up to and including 5/8" 3/4" to 1" inclusive Strength Specifications Thread "Proof Load" Stress lbf/in2 SAE Grade 5 UNC 120.428 . UNF.559 .088 1.0 12.398 11. 05 8. Min.00 9.F A S T E N E R Nyloc Nuts Metric S Table 56 Dimensions.00 18.5 46.2 28.8 – AS 1285 P.5 M12 1.67 21.0 36.95 22.85 36.50 17.00 7.20 14.C.5 8 5.66 5. Max.78 11. M4 0.0 16.50 60.00 45.5* 33.78 9.42 M24 3.60* 57.0 – – M6 1.5 17.5 8.60 39.75 18.30 M30 3.3 4.30 20.8 8.6 – Fasteners your guarantee of quality industrial fasteners 65 .67 27.60 32.00 6.00 53.70 26. except those with asterisk. – Min.5 M10 1.90* 23.55 28.0 2.09* 50. Max. comply to AS 1258 Pitch Nom.00 53.02 11.10 14.0 13. M5 0.20 8.25 13.30 M36 4.00 14.16 34. Min.0 75.15* Mechanical P Type P Type T Type T Type Properties: M4-M24 M30-M36 M6-M16 M2G-M36 Proof Proof Proof Proof Load Load Load Load Stress Stress Stress Stress 800 400 600 400 MPa MPa MPa MPa AS 1285 P.20* 32.00 35.10 50.2 22.0 10 6.20* 28. Min.0 19.90* 20.0* 5.0 55.0 23.90 11.00 12.80 63.73 19.5 30.5 65.20* M48* 5.10* 72.0 12 8 M16 2.0 16 10.50 11.00 23.00 41.60* 82.00 16.78 8.0 10.0 6 4 – M8 1.79 6.73 15.00* 63.0 10.00 29.30 M42* 4.10* 86.30 24.0 20. Thread s Across Flats e Across Corners h m h m P TYPE T TYPE Nut Thread Nut Thread Height Height Height Height Max.85 9.90 21. of Dia.5* 37.5 6.38 9.10 7.C.79 43.60 18.5 M20 2.0 24.7 7.90 Max.75 19.00* 73.80* 75. 294 .710 1.560 1.580 2.480 1.515 .990 .585 . h m h m P TYPE T TYPE Nut Thread Nut Thread Height Height Height Height Max.528 .355 1.610 .695 .565 1.985 1.239 .190 2.333 .760 2.535 .445 .270 1.190 .010 .593 .815 2.730 11/2 6 2. Min.175 1.156 3/8 16 .860 1.Nyloc Nuts BSW F A S T E N E R S Table 57 Threads Nom.762 .378 .065 .600 .740 .113 .254 .640 1.319 .710 .520 2.905 .820 .125 1.525 .321 . .240 . Min.950 .146 2 Mechanical Properties: P Type Proof Load Stress 28 tonf/in2 T Type Proof Load Stress 14 tonf/in2 (432 MPa) (216 MPa) AS 2451 Fasteners your guarantee of quality industrial fasteners 66 .302 .220 2.980 1.390 .820 .170 .490 1 8 1.700 3.734 1.656 11/4 7 1.150 1.200 1. per Dia.440 1.670 1.438 .5 2. .300 1. inch s Across Flats e Across Corners Max.365 3/4 10 1.435 . 3/16 24 . – – 1/4 20 .800 .730 1.821 .552 .677 .450 1.427 .365 .374 Max.267 Min.573 11/8 7 1.156 Max.985 1.896 13/4 5 2.123 5/16 18 .447 .500 1.175 2.510 .063 4.960 .930 1.105 1.274 .012 .198 7/16 14 .448 7/8 9 1.450 1.690 .731 .324 .722 .403 .865 .281 5/8 11 1.605 1.240 1/2 12 . Proof Load Stress 120.416 1.220 .335 .328 .758 .564 .565 2.615 1.890 .468 . .052 1.939 3. per inch Dia.877 .098 . Min.689 1.615 .662 3.312 1.324 .875 1. Ref.840 .125 3.328 .631 1.698 .553 .450 1.051 .128 .464 .328 .765 .468 .060 Properties: 1/4" – 3/4" 7/8" – 2" 1/4" – 3/4" 7/8" – 2" 1/4" – 11/2" 1/4" – 11/2" Max.421 .5 12 Mechanical UNC P Type UNC P Type UNF P Type UNF P Type UNC T Type UNC T Type s Across Flats e Across Corners Max.449 2.627 .982 .593 .935 1.430 .000 tonf/in2 (827 MPa) (621 MPa) (952 MPa) (621 MPa) (496 MPa) (448 MPa) – – AS 2465 G5 AS 2465 G2 AS 2465 G5 AS 2465 G2 Fasteners your guarantee of quality industrial fasteners 67 .826 1.250 .752 .225 .F A S T E N E R Nyloc Nuts YNC/UNF S Table 58 Threads Nom.406 .000 tonf/in2 Proof Load Stress 165.190 .269 1.265 1.523 2.940 .025 3.255 .765 .812 2.000 tonf/in2 Proof Load Stress 109.439 . UNC UNF 1/4 5/16 3/8 7/16 1/2 9/16 5/8 3/4 7/8 1 11/8 11/4 11/2 13/4 2 20 28 18 24 16 24 14 20 13 20 12 18 11 18 10 16 9 14 8 12 7 12 7 12 6 12 5 12 4.656 .158 .484 .949 – 1.928 1.064 1.688 1.618 1.367 1.288 1.302 .348 .865 . Ref.609 .250 2.000 tonf/in2 Proof Load Stress 90.828 .469 – .038 1.500 1.405 1. h m h m P TYPE T TYPE Nut Hex Nut Hex Height Height Height Height Max.742 .035 2.240 .022 .052 1.502 .000 tonf/in2 Proof Load Stress 72.492 .224 .175 2.557 .000 tonf/in2 Proof Load Stress 90.488 .578 .340 1.858 .492 1.359 .365 1.741 .750 2.191 .628 .265 . Max.225 .040 .447 1. The lock nut must always be assembled on the bolt first and pulled up snug. and as it is tightened the threads of the lock nut must first bear upward on the bolt threads. it should always be placed as shown in Fig 49. It should be applied with only moderate initial torque. The top nut should be wrenched on the full torque requirements.Correct Use of Jam or Lock Nuts F A S T E N E R S Thus the two nuts are bearing in opposite directions on the threads and are jammed. not as in Fig 48. then are free. since most of the tension is now being supplied by the top nut. while the threads of the top nut bear upwards on the bolt threads. The final bolt tension is therefore higher than that originally set up by the bottom nut. The top nut is then assembled. Conclusion The bottom nut should be the Jam or Lock Nut. and may in fact be higher than could be sustained by the bottom nut alone. This locking effect will remain even if the bolt tension is lost. the bottom nut should be held from turning. but not tightened severely enough to produce a high tension in the bolt. When a Jam or Lock Nut is to be used. During final wrenching. Fasteners your guarantee of quality industrial fasteners 68 . and finally bear downward on the bolt threads. It should not have a tight thread fit. Only after the plating metal has been significantly lost to corrosion does corrosion of the base metal begin. enameling and dip and bake are special purpose and economically impractical for stock commercial fasteners. such treatments also enhance appearance. chemical vapour deposition. and assist product identification. In an electrochemical reaction. which is a chemical conversion process to cover the zinc surface with a hard non-porous film. Metallic Coatings Zinc is by far the most widely used plated metal followed in popularity by cadmium and aluminium. When the base coating is breached. protects it against early tarnishing. stainless steel and most other nonferrous metals used in fastener applications. hot-dipping or mechanically. Copper. Zinc Zinc is favoured as a plating metal because in the Galvanic Series it is less noble than carbon steel. which has modest use. Because of its unsightly appearance. most zinc plated fasteners are given chromate treatment. vacuum metalising. Other plating metals are more noble than carbon steel. iridescent. Although the principal reason is to protect against corrosion. Chromate coatings are available clear. Zinc is the popular fastener coating also because it is the least expensive. For commerical fasteners. and is relatively nontoxic. has good appearance. Fasteners your guarantee of quality industrial fasteners 69 . nickel. and through its sacrifice. the base metal comes under immediate attack. chromium. coated or furnished with some other type of supplementary finish.F A S T E N E R S Corrosive Protective Coatings Acknowledgement is made to the American Industrial Fasteners Institute for information in this article Corrosion Protective Coating Approximately 90% of all carbon steel fasteners are plated. practically all deposition is accomplished by electroplating. Also zinc coatings without some supplementary protection develop a dull white corrosion product on their surface which is nicnamed "white rust". ion plating. can be applied in a broad range of thickness. This added coating effectively seals the surface. minimise thread seizing. tin. and reinforces the fastener's resistance to corrosion attack. Coating Coatings are adherent layers applied to the surface of a base metal. Other processes such as spraying molten metal. Zinc plated fasteners may require more tightening torque to develop equivalent preloads in threaded fasteners. control installation torque-tension relationships. lead and silver are used to a lesser degree – all for special reasons. or in a variety of colours. the plating metal corrodes. by self passivation has good-to-excellent corrosion resistance. the base metal remains protected. which in engineering standards are expressed in terms of mass of plating metal deposited per unit area of a coated surface.003 (80µm) are feasible. is proportional to the thickness of its plating.002in over 40 years in a rural atmosphere. the relative corrosion combating performance of zinc electroplated and hot-dip galvanised fasteners compared with mechanically plated fasteners has been under investigation. Consequently. 5µm.0002in. fastener service life. However. In the fastener's threaded section. Mechanically plated coating thicknesses are available through the full range offered by either electroplating or hot-dip galvanising. Thicker electroplatings are possible but. the thickest plating is located at the thread crests and becomes progressively thinner on Fasteners your guarantee of quality industrial fasteners 70 S . Useful service life expectancies of zinc plated fasteners in various environments are: Zinc plated with chromate treatment. A F A S T E N E R range of exposure environments indicated equivalent performances for fasteners having the same coating thickness. 2 years in coastal locations and less than 1 year in heavily polluted industrial atmosphere.002/in2 (50µm in thickness). plating is expensive. Plating Distribution The build up of plating on fastener surfaces occurs differently with each of the principal deposition methods. Survivability is almost a direct function of coating thickness. from an economics viewpoint. 25-30 years in coastal locations and 5 years or longer in heavily polluted industrial atmosphere. the prudent engineer is advised to specify only that thickness of plating required to satisfy the application. Heavier coatings to . Hot-dip galvanising produces much thicker coatings. but such coatings may necessitate adjustments in mating thread fits to a degree that the fastener's strength properties may be adversely affected. quite impractical. Electroplating deposits the plating metal unevenly with exterior edges and corners receiving thicker coatings. 12µm.0005in. Costs – and attendant problems – increase with increasing plating thickness. in a corrosive atmosphere. Hot-dipped galvanised with an average thickness of 0. Standard hot-dip galvanised fasteners have an average thickness coating of . Life Expectancy For several years.0005in plating thickness: up to 20 years indoors.Corrosive Protective Coatings Plating Thickness As a general rule. about 4 years in a rural atmosphere. The thicker the plating the longer it will survive. Electroplated fasteners have plating thicknesses ranging from a "flash" coating of insignificant thickness to a "commerical" thickness of 0. 0. through to 0. the actual fracture of the fastener into two separate pieces. it is usually impactical to hot-dip galvanise fasteners of nominal sizes smaller than M10 (3/8"). fasteners are thermally baked as early as possible after plating. are vulnerable to the one known as hydrogen embrittlement. Baking is always done prior to chromating or application of any other supplementary coating. which evidences itself in various mechanisms. In broad terms. with the thinnest deposits in the thread roots. Hydrogen embrittlement causes fastener failures. Plated and coated fasteners. With hot-dip galvanising. with thicker coatings deposited at interior corners and in the thread roots. The failure occurs in service (ie after the fastener has been installed and tightened in its application). The purpose of the baking – generally at 190°-210° for 3 to 24 hours dependent on plating type and thickness – is to drive out the hydrogen by bleeding it through the plating. Because mechanical plating is nonelectrolytic. some accommodation must be made prior to plating. Time delays seriously jeopardise the effectiveness and benefits of the baking. When interference between mating threads is likely. the hydrogen embrittlement thread is virtually Fasteners your guarantee of quality industrial fasteners 71 . Because clogging of thread roots is difficult to control. Mechanical plating tends to deposit the plating metal similarly to hot-dip galvanising but more smoothly and considerably more uniform in thickness over the entire surface. Hydrogen Embrittlement High strength. it usually happens within hours. When the plating thickness exceeds certain limits – generally one-fourth of the specified allowance for the class of thread fit – there is a distinct possibility the internally and externally threaded parts will not assemble. To neutralise the threat of hydrogen embrittlement. Recommended practices for adjusting thread fits of plated fasteners are discussed in AS 1897-1976. fasteners with hardnesses less than Rockwell C32 have a low risk of embrittlement. it's sudden. high hardness carbon steel fasteners have a susceptibility to embrittlement.F A S T E N E R S Corrosive Protective Coatings the thread flanks. there's no advance warning or visible indication of imminence. especially those that are electroplated. Thread Fit The addition of a plating to its surface increases the size of the fasteners. Plating Problems Two serious problems are directly attributed to plating – thread assembly and hydrogen embrittlement. it is just the opposite. Those with higher hardnesses should always be suspect. However. Dry zinc phosphate is often used as a base for nonmetallic locking elements on externally threaded fasteners. parts with hardnesses up to Rockwell C55. The phosphate base provides an excellent substrate for painting and for retention of oils. AS 1252 – 8.8.8 and AS 2465 – Grade 5. susceptibility and frequency of occurrence are less than similar fasteners which have been electroplated. or manganese phosphate often used as a permitted alternative.Corrosive Protective Coatings eliminated. phosphate coatings do not significantly increase fastener size. particularly those intended for use in automotive application. Significant improvements are possible through secondary treatments. are extensively specified for fasteners. The primary reason is that engineering standards strongly discourage the hot-dip galvanising of fasteners with hardnesses higher than Rockwell C35 – ie fasteners stronger than AS 1110 – 8. have performed satisfactorily without evidence of embrittlement. Chemical conversion coatings popularly specified for fasteners are chromate treatments on electroplated parts (mentioned earlier) and zinc and manganese phosphate coatings. waxes or other organic lubricating materials. One of the more important considerations when evaluating the possible use of phosphate coated fastener is cost. Rarely is it necessary to make adjustments in thread size limits prior to coating. Hot-dip galvanised fasteners are rarely subject to hydrogen embrittlement. The corrosion resistance of zinc phosphated and oiled fasteners is reasonably good in nonaggressive atmospheres. mechanically plated without post baking. Chemical Conversion Coatings Chemical conversion coatings are adherent films chemically formed on a metal's surface when immersed in a bath of appropriate solution. F A S T E N E R Most zinc phosphated fasteners are additionally oiled to enhance corrosion resistance and to help control torque-tension relationships. Although phosphate-coated high strength fasteners are not immune to hydrogen embrittlement. the packaging and handling of phosphate and oiled fasteners has a degree of sensitivity because the oil may be removed by absorption into the packing materials. such as painting. In fact. Tolerance 6g/6H (Class 2A/2B) screw thread fits are usually adequate to permit assembly. Phosphate and oiled coatings are less expensive than zinc electroplating with chromate treatment. Fasteners your guarantee of quality industrial fasteners 72 S . Unlike deposited plating. The reason is that galvanised fasteners of higher strengths have a susceptibility to another embrittlement mechanism known as stress corrosion or stress corrosion cracking. Zinc phosphate coatings. AS 1627. AS 1111-1980 ISO Metric Hexagon Commercial Bolts and Screws. AS 1214-1983 Hot-dip Galvanised Coatings on Threaded Fasteners (ISO Metric). AS 1112-1980 ISO Metric Hexagon Nuts. Nuts and Washers. aluminium).6-1977 Phosphate Treatment of Iron and Steel Surfaces. AS 1897-1976 Electroplated Coatings on Threaded Components (ISO Metric). AS 2465-1981 Unified Hexagon Bolts. Australian Standards associated with corrosion protective coatings are: Metric Inch AS 1110-1984 ISO Metric Hexagon Precision Bolts and Screws. AS 1559-1986 Fasteners – Bolts. AS 1791-1986 Chromate Conversion Coatings Zinc and Cadmium.2-1973 Electroplated Coatings on Threaded Components (Zinc on Steel).F A S T E N E R S Corrosive Protective Coatings Fastener Coating Selection Chart Table No 61 is condensed from Blacks Bulletin No. AS 1252-1983 High Strength Steel Bolts with associated Nuts and Washers for Structural Engineering (ISO metric). AS K132. AS B108-1952 Black Cup and Countersunk Bolts. 6-69. AS 1390-1974 Metric Cup Head Bolts. Fasteners your guarantee of quality industrial fasteners 73 . where materials other than steel are included (eg stainless steel. Nuts and Washers for Tower Construction. It gives recommendations as to the finishes on steel bolts which are considered satisfactory – from the corrosion viewpoint – for the joining of metals which could cause "galvanic" effects. brass. Screws and Nuts (UNC and UNF threads). AS B193-1970 Hot-dip Galvanised Coatings on Fasteners (BSW and UNC threads). Monel U U U S U U Lead U U U S R S R Key to performance: R = Recommended S = Satisfactory U = Unsuitable NOTES 1.Corrosive Protective Coatings F A S T E N E R S Table 61 Metal Joined Bolt Coating GalZinc vanised Plated Cad. in the absence of painting. “Chromium plated” . Protection of the small area of the fastener depends on amount of zinc available on the surrounding galvanised surface.the greater the available amount of zinc the better. and then this bare steel could accelerate corrosion of the aluminium and also cause staining . Thus. Brass U U U U U U S Nickel.including the trade term “chrome plated” . Fasteners your guarantee of quality industrial fasteners 74 . the more heavily coated hot dipped galvanised fastening is a better choice than its zinc plated counterpart. 3. Cast Iron S S S S S R S Zinc Coated Steel R S1 S1 S S U S Tin Coated Steel U U U S U U R Chromium Plated Steel U U U R U U R Stainless Steel U U U S U U R Aluminium S3 S3 R S S U R Copper.Chrom.means plated with a thin layer of chromium over a more substantial layer of nickel (and perhaps copper). 2. causing accelerated corrosion of the zinc. Aluminium is the protected member of aluminium-zinc combinations. Since wastage of the zinc coating will eventually lead to exposure of the basis steel of the fastener.Lead Black or Austenmium ium /Tin Bright itic Plated Plated2 Plated S/Steel Steel. 211 26. will produce holes within the minor diameter limits shown.422 3.5 x 0. Letter and wire gauge drills are obsolescent and are being replaced by metric sizes.7 3.103 M2.647 6.051 No.270 31.35 1.5011 13/6415 – M36 x 4.8 4. Table 62 ISO Metric Coarse Pitch Series Thread Size and Pitch mm Minor Diameter of nut thread (A) Maximum Minimum Tapping Drill Sizes for Commercial Tapping Recommended Alternatives mm mm mm Inch mm M1.0 32.912 6. 469 2.679 1.302 M5 x 0.251 M2 x 0.676 8.553 M4 x 0.303 3/640 1.744 17.567 1.252 20.771 26. 193 4.210 13.006 M20 x 2. 301 3.0 21. As a guide to relative clearances.F A S T E N E R Tapping Drill Tables S The tapping drills given in the following pages include millimetre sizes for the convenience of those who are working in or intend to work predominantly in metric units.242 3.5 8.204 M16 x 2. when used with reasonable care.4011 13/328 35/642 – M12 x 1.294 17.221 1.00 5. 410 2.601 2.306 No.45 2.835 14.654 1/161 1.334 4.599 2.9010 17/644 6.670 32.501 M3 x 0.0010 53/ 11 64 – M30 x 3.505 10.752 21.134 4.6 x 0.25 6.107 No.5 26.806 M10 x 1.5 2.013 2.4 1.609 Q2 8. index figures adjacent to the drill size show the difference between the nominal drill and minimum minor diameters.75 10.003 M8 x 1. Drills have been selected from standard sizes which.5 17.0013 117/6419 – (A) From AS 1275 for Class 6H The small index figures show the theoretical clearance in thousandths of an inch above the minimum minor diameter of the nut thread.00 14.202 M6 x 1.133 4.406 No.138 No.459 2.105 10.441 10.321 1. Fasteners your guarantee of quality industrial fasteners 75 .508 11/167 – M24 x 3.376 8. From those drills the larger sizes are recommended to facilitate ease of tapping. 92 5.917 5. 2950 N7 7.6220 41/6419 16.3461 T12 9.007 0.1026 1.9420 31/3217 24.8400 11/8 – 7 0.5023 33/647 0.2030 0.708 19/642 S2 7/16 – 14 0.5016 15/6411 11/2 – 6 1.4169 0.9776 0.1020 0.0012 119/6411 13/4 – 5 1.4557 15/3213 12.7012 286 1/4 – 20 0.4938 117/3237 38.3932 13/3213 10.1341 2710 3.1474 0.0026 27/321 5/8 3/4 7/8 1 – 11 – 10 – 9 0.0015 47/642 55/6419 22.5408 1.1860 910 5.8720 0.6490 0. Letter and wire gauge drills are obsolescent and are being replaced by metric sizes.3145 0.2517 5/83 0.5338 0.2413 1/49 6.0930 397 2.4011 D5 C1 3/8 – 16 0.7154 13/435 44.5086 17/3223 13. The small index figures show the theoretical clearance in thousandths of an inch above the minimum minor diameter of the nut thread. Fasteners your guarantee of quality industrial fasteners 76 .2866 15/1626 33.5022 61/6411 11/4 – 7 1.557 405 3/16 – 24 0.4013 9/16 – 12 0.2594 0.7620 – 8 0.1012 Y11 X4 1/2 – 12 0.Tapping Drill Tables F A S T E N E R S Table 63 British Standard Whitworth – BSW Thread Size and Threads per inch Tapping Drill Sizes for Commercial Tapping Maximum Minimum Inch Inch Inch Recommended mm Alternatives Inch 1/8 – 40 0.5 1.0011 107 123 5/16 – 18 0.5022 133/6420 1.7328 3/417 19.3269 1.7668 From AS B47 – normal and medium classes.5037 147/6420 2 (A) Minor Diameter of nut thread (A) – 4.4794 0.0670 13/3227 27.3674 0. 8 ISO Metric Preferred Coarse Pitch Series Threads per inch Dia in mm Pitch in mm BSW BSF UNC UNF – – 32 36 1.5 5/16 18 22 18 24 4 0.5 7 4.5 0.5 5 4 – Fasteners your guarantee of quality industrial fasteners 77 .45 No.5 11/4 7 9 7 12 36 4 13/8 6 8 6 12 42 4.6 2 0.5 – 21/4 4 6 4.75 16 16 2 3/4 10 12 10 7/8 9 11 9 14 20 2. in inches No.25 9/16 12 16 12 18 10 1.8 7/16 14 18 14 20 6 1 1/2 12 16 13 20 8 1. 10 – – 24 32 3/16 24 32 – – 0.5 1 8 10 8 12 24 3 11/8 7 9 7 12 30 3.4 2.5 6 4 – 3 3.5 11/2 6 8 6 12 48 5 15/8 5 8 – – 56 5.5 13/4 5 7 5 – 64 6 2 4.5 – 21/2 4 6 4 – 23/4 3.F A S T E N E R Thread Screw Pitches S Table 64 Inch Series Dia.35 1/4 20 26 20 28 3 0.7 3/8 16 20 16 24 5 0.5 5/8 11 14 11 18 12 1. 6 86.3 45.3 392 40 – 371 181 81 1250 54 70.3 63.1 HV HRC 940 68 – – – – – 900 67 – – – – – 865 66 – – – – – 832 65 – 739 – – 800 64 – 722 – 772 63 – 705 746 62 – 688 720 61 – 697 60 674 59 653 Fasteners your guarantee of quality industrial fasteners 78 .3 72.4 65.9 71.1 69.4 75.9 60.8 81 .2 83.9 63.4 458 46 – 432 222 99 1530 62 73.5 66.1 60.4 72.1 84.2 84.0 49.2 57.3 633 57 – 595 – – – 76 79.5 1340 56 71.5 82.8 71.9 81.9 87.9 – – – 85 82.5 56.4 45.4 528 51 – 496 264 118 1820 68 76.8 85.9 46.3 75.8 64.7 52. -trator Tensile Strength (Approximate) lbf/in2 tonf/in2 N/mm2 x 1000 Rockwell Superficial Hardness No.8 423 43 – 400 201 90 1390 57 72.2 81.9 65.5 75.4 67.0 53.4 68.7 64.1 79.8 560 53 – 525 283 126 1950 71 77.8 73.5 402 41 – 381 188 84 1300 55 70.5 92.0 64.5 58 – 615 – – – 78 80.0 62.8 484 48 – 451 237 106 1630 64 74.2 58.1 71 .2 46.8 83.0 59.6 60.4 95 85.4 84.8 73.5 64.8 91.7 412 42 – 390 194 86.6 – 634 – – – 80 80.2 70.1 47.6 74.4 92.3 68.1 85.0 66.4 70.1 69.1 57.5 471 47 – 442 229 102 1580 63 74.4 80.9 577 54 – 543 292 130 2010 72 78.2 91.4 60.6 68.0 60.2 77.9 62.6 82.3 – 91 83.0 595 55 – 560 301 134 2080 74 78.5 66.8 63.0 91.4 56.6 76.2 613 56 – 577 – – – 75 79.6 544 52 – 512 273 122 1880 69 76.4 73.4 44.0 434 44 – 409 208 93 1430 58 72.4 86.0 – – 88 83.7 – 654 – – – 81 81.5 82.9 93.4 59.5 58.7 61 .0 – – – 87 82.15kg 30kg 45kg -trator Load Load Load HRA HRD HR 15-N HR 30-N HR 45-N 97 85.9 83.1 513 50 – 481 255 114 1760 67 75.0 498 49 – 469 246 110 1700 66 75.8 65.5 55.0 90.0 67.8 670 – – – 83 81.9 74.7 88.5 66.0 76.7 69.5 88.3 446 45 – 421 215 96 1480 60 63.2 89.5 61.2 80.4 43.9 69.3 73.Hardness Conversion Table F A S T E N E R S Table 65 Rockwell C-Scale Vickers 150kg Hardness Load Brale Pene-trator Rockwell B-Scale 100kg Load 1 1 /16" dia Ball Brinell Hardness No. 3000kg Load 10mm Ball HRB HB Rockwell A-Scale Shore 60kg Sclero Load scope Brale Hardness PeneNo.8 50.8 51.5 63.0 57.1 92.5 90. Rockwell Superficial Brale D-Scale Penetrator 100kg Load 15-N 30-N 45-N Brale Scale Scale Scale Pene.7 78.8 86.2 62.9 89.0 67.7 74.1 87.0 83.9 73.2 92 84.9 72. 5 579 26 173 (4) 85.3 78. 3000kg Load 10mm Ball Tensile Strength (Approximate) Rockwell A-Scale Shore 60kg Sclero Load scope Brale Hardness PeneNo.5 165 80 35.6 79.6 41.5 43.4 53.6 72.0) 247 120 53.7 27.3 254 23 100.5) 138 61 .1 171 84 37.5 1030 46 66.3 34.0 243 117 52 807 36 62.5) 311 149 66.4 52.0) 271 132 59 910 41 64.3 44.0) 294 142 63.6 72.2 63.4 57.0) 336 162 345 35 (108.9 38.2 45.8 43.8 45.8 272 26 (102.8 226 110 49 758 34 60.6 70.7 51.9 51 69.7 219 106 47.2 54.5 179 87 39 600 27 180 (6) 87.8 77.1 71.4 31 .5 1050 47 67.3 294 29 (1 04.1 69.6 47.9 69.3 194 94 42 648 29 – – – – – 196 (10) 90.5 302 30 (105.1 33.8 72.3 47.2 76.5) 327 336 34 (108.0 62.5 260 24 (101.8 28.5 1000 44 66. -trator lbf/in2 tonf/in2 N/mm2 x 1000 Rockwell Superficial Hardness No.9 203 98 44 676 31 – – – – – 204 (12) 92.0 37.5 231 112 50 772 35 61.8 56.6 53.0 66.8 46.5 19.5 40.0) 327 33 318 32 310 286 Fasteners your guarantee of quality industrial fasteners 79 .0 40.9 53.0) 301 145 64.5 731 33 – – – – – 222 (16) 95.6 51.9 42.7 31 (1 06.4 43.2 36.1 68.6 28.0 74.7 266 25 (101.4 75.9 25.5 703 32 – – – – – 213 (14) 93.F A S T E N E R Hardness Conversion Table S Table 65 continued Rockwell C-Scale Vickers 150kg Hardness Load Brale Pene-trator Rockwell B-Scale 100kg Load 1 1 /16" dia Ball Brinell Hardness No.5 827 37 62.7 48.5 979 43 65.1 71.8 39.0 58.1 286 28 (104.5 41.7 75.5 931 41 64.5 531 24 HV HRC HRB HB 382 39 – 362 176 78.0 243 21 98.3 49.5 77.1 52.8 48.2 22.5 1120 49 68.8 1160 50 68.6 230 (18) 96.3 32. Rockwell Superficial Brale D-Scale Penetrator 100kg Load 15-N 30-N 45-N Brale Scale Scale Scale Pene.9 279 27 (103.5 951 42 65.4 41.9 (1 07.5 1180 363 37 – 344 168 75 354 36 (109.0 40.6 45.5 30.5) 253 122 54.5 1210 372 38 – 353 171 76.7 187 90 40 621 28 188 (8) 89.1 248 22 99.7 40.5 212 102 45.0 23.8 50.5 158 77 34.4 157 70 1080 48 67.0 24.7 238 20 97.3 47.7 55.5) 279 135 60.4 50.8 77.3 46.7 47.5 841 38 62.2 319 153 68.0 237 114 51 786 35 61.15kg 30kg 45kg -trator Load Load Load HRA HRD HR 15-N HR 30-N HR 45-N 52 69.0) 264 128 57 883 40 63.5) 258 125 56 862 38 63.0 44.7 54.3 20.5 552 25 166 (2) 83.1 (1 07.3 55.1 73. 0 90 – – – – 90 – 48.2 105 – – – – 95 – 52.5 427 20 120 – 66.0 86 – – – – 85 – 41. Superficial Brale Penetrator 15-N Scale 15kg Load 30-N Scale 30kg Load 45-N Scale 45kg Load HR 15-N HR 30-N HR 45-N The values shown in black type are agreed SAE-ASM-ASTM values as published in ASTM. Australian Standard B-161 indicates the limitations of accuracy of conversion. IMPORTANT All conversions must be regarded as approximate and applying only to steels.3 105 – – – – 100 – 56.5 455 21 130 – 71.Hardness Conversion Table F A S T E N E R S Table 65 continued Brinell Rockwell Rockwell Hardness C-Scale B-Scale No.5 490 22 140 – 75. Tensile strength conversions do not specifically apply to cold worked steels.7 152 75 33. Values in ( ) are beyond the normal range and are for information only.7 114 57 25. Fasteners your guarantee of quality industrial fasteners 80 .5 393 – 110 – 62. E-140 Table 2.7 143 71 31. Vickers 150kg 100kg 3000kg Hardness Load Load Load Brale 11/6" dia 10mm PeneBall Ball -trator Rockwell Rockwell A-Scale D-Scale Shore 60kg 100kg Sclero Load Load scope Brale Brale Hardness Pene. Values in blue type are given in SAE tables but are not agreed values.5 517 24 150 – 78.0 133 66 29. -trator -trator Tensile Strength (Approximate) lbf/in2 tonf/in2 N/mm2 x 1000 HRA HV HRC HRB HB 160 (0) 81.PeneNo.2 124 62 27.0 81 – – – – HRD Rockwell Superficial Hardness No. Impact wrenches or air powered screw drivers are not recommended.0 47.3 6. The customer’s complaint is that during installation the bolts are twisting off and/or the bolt’s threads are seizing to the nut’s thread. required will also vary.0 91.0 116.F A S T E N E R S The Torquing of Stainless Steel Stainless steel threads are notorious for galling or seizing during tightening. A high quality nickel anti-seize has been found to be very effective.7 M12 64. bolt diameter and proof stress.6 38.2 M8 18. Recommended torque values are calculated figures based upon several factors including friction.5 3. Consequently the torque values quoted can only be regarded as a guide and bench trials should be conducted first. the actual torque Tightening Torques for Stainless Steel (304 and 316) Metric Bolts Nominal Diameter Grade Grade A2-70 and A4-70 Recommended Assembly Torque to include 70% Proof Load A2-80 and A4-80 Recommended Assembly Torque to include 70% Proof Load (NM) (ft lbf) (NM) M5 4.6 11.0 52.0 227.3 M16 158. In addition an antiseize compound must be applied to the threads.4 13.8 How To Stop Thread Galling on Stainless Fasteners A few times each year we receive calls from fasteners suppliers who are in conflict with their customer over the quality of stainless steel bolts and nuts.0 163.7 223.1 8. during the bench trials the torque required to start permanent stretching of the bolt should be noted. The frustration of the supplier is that Fasteners your guarantee of quality industrial fasteners 81 .8 M6 7.6 5. Applying 70% of this torque figure will be a safe installation torque.5 (ft lbf) 4. As the use of anti-seize is going to vary the friction characteristics of the assembly.0 27.9 M20 309.5 67.7 435.6 M10 37. For a successful assembly. Standard engineering practice requires fasteners to be tightened to a point where the included screw tension is 65-70% of the proof load. tightening should be carried out with a slow smooth action. Therefore. Once the proof load is exceeded the bolt will start to stretch permanently.7 19.0 319.6 26. mica.” Carpenter Technologies. If tightening is continued. the fastener can be twisted off or its threads ripped out.oly). One such source. This is because the different alloys work harden at different rates. You must be aware of the end use for the fasteners before settling on a lubricant. galling leads to seizing – the actual freezing together of threads. This problem is called “thread galling”. protective oxides are broken. • Using different stainless alloy grades for the bolts and nut reduces galling. This cumulative clogging-shearinglocking action causes increasing adhesion. or talc. waxes may also be effective. In the extreme. so does the tendency for the occurrence of thread galling.Mechanical Properties of Stainless Steel all required inspections of the fasteners indicate they are acceptable. EM Corporation. as pressure builds between the contacting and sliding. Lubricants can be applied at the point of assembly or preapplied as a batch process similar to plating. titanium and other alloys which self-generate an oxide surface film for corrosion protection. the fastener industry’s largest supplier of stainless steel raw material. The IFI and Carpenter Technologies give three suggestions for dealing with the problem of thread galling in the use of stainless steel fasteners: • Slowing down the installation RPM speed will frequently reduce. thread surfaces. suggests their Permaslik® RAC product for use at the point of assembly. the problem. possibly wiped off. • Lubricating the internal and/or external threads frequently eliminates thread galling. The key here is the mating of materials having different hardnesses. They suggest Everlube® 620C for batch. As the F A S T E N E R installation RPM increases the heat generated during tightening increases. extreme pressure. Stainless steel is frequently used in food related applications which may make some lubricants unacceptable. graphite. If one of the components is 316 and the other is 304 they are less likely to gall than if they are both of the same alloy grade. As the heat increases. or sometimes solve completely. The suggested lubricants should contain substantial amounts of molybdenum disulfide (. Another factor affecting thread Fasteners your guarantee of quality industrial fasteners 82 S . During fastener tightening. but the fact remains that they are not working. and interface metal high points shear or lock together. “Thread galling seems to be the most prevalent with fasteners made of stainless steel. aluminium. refers to this type of galling in their technical guide as “cold welding”. Some proprietary. According to the Industrial Fastener Institute’s 6th Edition Standards Book (page B-28). Several chemical companies offer antigalling lubricants. pre-applying to stainless steel fasteners. Anyone who has seen a bolt and nut with this problem understands the graphic nature of this description. but when they do it usually creates a customer crisis. Are you using the same grade of stainless steel for the bolts and nuts? Here are some questions that should be asked and the suggestions that should be made immediately when you are confronted with a customer’s complaint about thread galling: 1.F A S T E N E R S Mechanical Properties of Stainless Steel galling in stainless steel fastener applications is thread roughness. the greater the likelihood galling will occur. Are the bolts and/or internal threads lubricated? If they say “no”. In general. If they say they are driving them faster than in the past or if they say this is a new application. a stainless bolt of a given size should be driven slower than a steel bolt of the same size. Internal threads are always cut. The rougher the thread flanks. suggest they try lubricating the bolts and/or internal threads with one of the lubricants listed earlier in the article. In an application where the bolt is galling with the internal thread. Bolt threads are generally rolled. producing rougher thread flanks than those of the bolts they are mating with. Try the suggestions listed. In applications where galling is a repetitive problem. suggested they immediately try slowing the driver RPM and see if the problem goes away. their thread flanks are relatively smooth. Be sure the suggested grade meets their corrosion needs and changing the material does not cause a procurement problem. the bolt is usually presumed to be at fault. Knowledge of why this occurs and how to remedy it can save the supplier much grief and many headaches. If this eliminates the galling. do not panic. Generally. you might want to batch lubricate the remainder of the order to eliminate the extra work of applying lubricant at the point of assembly. Rougher than normal internal threads may be the result of the use of dull taps or the tapping may have been done at inappropriately high RPM. Are you using the same driver RPM you have used in the past to install these stainless fasteners? 2. If the answer is “yes”. stainless steel bolt and nut galling problems do not occur everyday. Fasteners your guarantee of quality industrial fasteners 83 . Fortunately. one or a combination of these will probably resolve the problem immediately. therefore. 3. because it is the breaking component. When thread galling occurs in stainless steel bolt and nut applications. This is because most bolt threads are smoother than most nut threads. it is advisable to supply the fasteners with preapplied lubrication to eliminate future problems. The reason galling problems are inconsistent is probably due largely to the inconsistencies in the tapping operation. you can suggest changing one or the other to a different grade. it is the internal thread that is causing the problem instead of the bolt. Some corrosion may occur in marine/ industrial environments.84 NO NO Copper NO ? NO YES YES YES NO NO ? I L YES YES YES NO NO Brass T Compatible in rural and mild environments. Painting both metals would reduce reaction. YES YES YES NO NO Copper A S INCOMPATIBLE Must not be in contact ? ? Stainless Steel NO NO NO Nickel Copper YES ? Stainless Steel R A COMPATIBLE YES NO Steel Z/P E Zinc Coated Steel T F YES YES YES Aluminium A AL/ZN Coated Steel M Aluminium Rivet Material Compatibility Material Compatibility E N E R Fasteners your guarantee of quality industrial fasteners S . Sydenham T: (03) 365 2460 F: (03) 365 2464 CHRISTCHURCH 521c Blenheim Road.Fastener Handbook BLACKS FASTENERS LTD AUCKLAND 930c Great South Road T: (09) 589 1036 F: (09) 589 1037 NELSON Corner Brilliant Place and Nayland Road T: (03) 547 5102 F: (03) 547 0189 CHRISTCHURCH 39a Gasson Street.blacksfasteners.co.nz Established 1989 . Sockburn T: (03) 348 0340 F: (03) 348 0346 INVERCARGILL 156 Bond Street T: (03) 214 4499 F: (03) 214 4489 Freephone: 0800 652 463 Freefax: 0800 652 464 www.