IS 2102 ( Part 1 ,) : 19932768-l : 1989 IS0 ( Reaffirmed 2003 ) UDC 621’753’1 : 744’4 @ BIS 1993 iBUik@AlJ Of INDIAN hk4W4ft $Ha4VhW,9 BAHADUR NEW OELHL STANDARDS SHAH 110002 ZAFAR MARG for features - Part 2: Geometrical tolerance indications. Members of IEC and IS0 maintain registers of currently valid International Standards.g.g.g. see IS0 806211. reference shall be made to them on the drawings or associated specifications. This part of IS0 2758 only applies for the following dimensions which do not have an individual tolerance indication : 3 It applies to the dimensions of parts that are produced by metal removal or parts that are formed from sheet metal. NOTES 2 Thesetolerancesmay be suitablefor use with materialsother than metal. Technical drawings b) 4. unless reference to IS0 2768-2 is made.linear and angular dimensions apply when drawings or associated specifications refer to this part of IS0 2768 in accordance with clauses 4 and 5. radii. a) linear and angular dimensions which are covered by reference to other standards on general tolerances. constitute provisions of this part of IS0 2768. e. external radii and chamfer heights for broken edges). including angular dimensions usually not indicated.IS 2102 ( Part 1) : 1993 IS0 2768-l : 1989 Indian Standard GENERAL PART 1 TOLERANCES FOR LINEAR AND ANGULAR DIMENSIONS INDIVIDUAL TOLERANCE INDICATIONS ( 1 TOLERANCES WITHOUT Third Revision ) Scope This part of IS0 2758 is intended to simplify drawing indications and it specifies general tolerances for linear and angular dimensions without individual tolerance indications in four tolerance classes.g. through reference in this text. for castings.1 1) IS0 8062 : 1904.System of dimensional tolerances. the respective customary workshop accuracy has to be taken into consideration. . Fundamental toleran- cing principle. diameters. e. e. 2 General When selecting the tolerance class. a) linear dimensions (e. Normative General tolerances Linear dimensions General tolerances for linear dimensions are given in tables 1 and 2. references The following standards contain provisions which. For a dimension between an unfinished and a finished surface. It does not apply for the following dimensions : IS0 2758-Z : 1989. e. General tolerances for . cl linear and angular dimensions produced by machining assembled parts. At the time of publication. internal sizes. auxiliary dimensions indicated in brackets. external sizes.g.The conceptsbehind the generaltolerancingof linearand angulardimensionsare describedin annex A. right angles BOoI. such tolerances should be indicated adjacent to the relevant nominal dimension(s). If smaller tolerances are required or larger tolerances are permissible and more economical for any individual feature. Castings . If there are general tolerances for other processes. the larger of the two general tolerances in question applies. step sizes. distances. 3 Parallel International Standards exist or are planned. All standards are subject to revision. of cast or forged parts. see IS0 60621)for castings. b) angular dimensions. the editions indicated were valid. as specified in other International Standards. or angles of uniform pclygons. and parties to agreements based on this part of IS0 2768 are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. General tolerances tolerances without - individual IS0 8015 : 1985. 4 c) theoretically exact dimensions indicated in rectangular frames. for which no individual tolerance is directly indicated. NOTE 1 . 8 +1.8 -L 1.5 mm. shall not lead to automatic for linear dimensions radii and chamfer heights.5 f4 +6 +_8 V 1) 6 very coarse For nominal sizes below 0.5 f0.IS 2102 ( Part 1) : 1993 : 1969 IS0 2766-l 4. except for broken edges see table 2) Values in millimetres Tolerance Permissible class n c11 I I 1 over over ) deviations 1 for basic size range over 1 over 1 over 1 over 1 over Description Designation I 36 126 400 loo0 2066 46cm f fine i 0. in millimetres.2 *0. the deviations shall be indicated adjacent to the relevant nominal size(s).3 kO.5” / fine I / medium C coarse V very deviations up to 3 over 3 for basic size range up to 6 over 6 * 0. Rejection Unless 5 Indications otherwise tolerance on drawings ability If general tolerances in accordance shall apply.3 kO. only the b) the tolerance but not IS0 2768.very coarse deviations Permissible class f C Permissible of angular dimensions deviations for ranges of lengths.5 fl f 0.3 +0.5 kO.5 kl +1.15 f 0. of the shorter side of the angle concerned up to 10 over 10 up to 56 f10 + 0030’ -__+ 30 220 2 over 56 up to 120 over 120 up to 406 over 4lXl + 0020 + 0010’ + 005 It 090 kOO15’ ltOOl0 k OY?O’ f 0020’ +1o .1 fO. Table 2 - Permissible deviations for broken edges (external radii and chamfer heights) Values in millimetres Tolerance Designation f ---__ m _~ -___.05 k 0.2 Angular General a) “IS0 2768”. Table 3 Tolerance Designation Description fine m medium V ~____ coarse -.05 f0. the following near the title block : with this part of IS0 information Table 1 - 2768 shall be indicated Permissible workpieces of the workpiece to rejection function general provided that the is not impaired (see clause A.5 mm. The maximum distance between line of ideal geometrical the contacting the actual line shall be the least possible value (see IS0 The permissible deviations of angular dimensions IS0 2768-m line and 8015). the deviations shall be indicated adjacent to the relevant nominal size(s).5 f2.4 +1 +2 coarse 1) For nominal sizes below 0.1 kO.2 +0.2 +0.2 f2 +3 +4 - f0. dimensions tolerances specified general orientation in angular units control of lines or line elements of surfaces.2 *2 C coarse +_0. class Permissible Description 0. class in accordance with this exceeding the part of their form deviations.l f 0. are given in 6 table 3. EXAMPLE The general orientation face is the orientation of the line derived from the actual sur- of the contacting form.2 + 0. in or deviations (external stated.4).5 - m medium f0. The workshop should. defining the function to or larger tolerance purchase a tolerance falls outside the scope of general tolerances. b) is placed. for the most pat-t.e. the required The accuracy general of “good workmanship”. the larger tolerance a) can “customary exceeded. Rrprogr*phy Unit. tolerances capability. However. Relying on undefined “good workmanship” tainties and misunderstandings concept Using general tolerances what is. therefore - find out workshop by accuracy measurements accept only those drawings equal to or greater its customary having general than its customary - economy. time de- only to know greater than or equal to the function allows is often greater The function of the part is. leads to the following advan- : of geometrical general tolerances geometrical define with all its uncer- is no longer necessary with the tolerances. there is usually no gain by enlarging of conformance accuracy”. always impaired when the general tolerance exceeded at any feature of the workpiece.4 to the user of the drawing. therefore. In these special cases. a feature value than the “general cent to the dimension tolerance plan- services in their analysis plete. to the dimension as described orders more accuracy” and the supplier. BIS. In cases where equal reasons. be those control- and which therefore the production the process quality engineering clause 5. for which the function could be manufac- Specifying *0. class being selected and indicated to the requirement to the tolerance d) appropriate on the drawing ac- those dimensions ling features for the components.IS 2102 ( Part 1) : 1993 IS0 2768-l : 1989 Annex A (informative) Concepts A. the of a feature general adja- This type of adjacent allows tolerance a tolerance values. For in a workshop in this particular of of inspection also which have individually ning and will assist quality control A.1 by General reference behind tolerances to this general tolerancing should be indicated part of IS0 2768 of linear and angular c) on the drawing in accordance values classes of tolerance cording readily indicates which feature by normal of general tolerances customary correspond workshop accuracy. should be indicated tolerances workshop accuracy.’ when workshop the customary workshop accuracy of the is equal to or finer than the general tolerances indicated in the drawing. e. New Dclbi.2 can be pro- which will.g.3 mm - e) if. the depth of blind holes drilled at assembly. drawings are easier to read and thus communication made more effective is A. Above certain tolerance in manufacturing example. inspection remaining. should requires relatively small requirements. check by sampling that its customary workshop accu- racy does not deteriorate. by reducing dicated tolerances. be of no benefit tolerance values tolerance. for the particular feature. The tolerance the general tolerance. This type of allows full use of the concept There will be “exceptions feature and workshop. readily allows is known before the contract on delivery than the general will provide manufacturing individually adjacent to the dimension of the the buyer is com- are fully that the obtained only when there is general tolerances will not be i. tolerances. for functional have the smaller than should not be indicated be stated on the drawing tolerance sub-contract of workshop as this also avoids arguments be quite then that feature indicated individually its size or angle. India . between of general tolerancing. negotiate adequate. general tolerance should only if the function lead to a rejection than not is ioccasiorlallv) Exceeding the of the workpiece is impaired. tolerance in- may require special effort in this will be helpful for production with would assists levels. requires a smaller tolerances”.3 supply since these in clause 5. particular but should to the rule” where the function a larger tolerance and the larger tolerance tages engineers the since in this respect the drawing These advantages sufficient reliability - A. The the drawing duced with dimensions the design tailed tolerance that the function draughtsman calculations saves by avoiding as it is sufficient allows a tolerance the general tolerance. tured economy a feature to a high “customary general the having a 35 mm diameter level medium k 1 mm would values. 9 Bahadur Shah Zafar Marg.established under the Bureau of Indian Stunt. it is taken up for revision. Sector 34-A CIiANDi&RH 160022 Southern : C. basis of comments. IV Cross Road. V. Standards are also reviewed periodically.832 78 it3 5g bE ( 832 832 92 78 95.Bureau of Indian Standards BIS is a statutory institution .323 94 02 Regional Offices: Telegrams: Manaksanstha (Common to all offices) T&phone .I. I&u&d k&e Publication’ Date of Issue BUREAU Text Affected OF INDIAN STANDARDS Headquarters: Manak Bhavan. This Indian Standard has been developed from Dot: No. if the review indicates that changes are needed.832 Branches : . of necessary details. CHENNAI 600113 t 26. Copyright BIS has the copyright of all its publications. 323 38 41 Northern : SC0 335-336.@& Act. No part of these publi&tions may be reproduced in any form without the prior permission in writing of BIS.337 9i ri5 6i 2b 337 84 86 99.T. 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