1、raising standards worldwide NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW BSI Standards Publication BS ISO 888:2012 Fasteners Bolts, screws and studs Nominal lengths and thread lengthsBS ISO 888:2012 BRITISH STANDARD National foreword This British Standard is the UK implemen
2、tation of ISO 888:2012. It supersedes BS 7345:1990 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee FME/9/2, Fasteners - Reference Standards. A list of organizations represented on this committee can be obtained on request to its secretary. This public
3、ation does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2012. Published by BSI Standards Limited 2012 ISBN 978 0 580 71176 3 ICS 21.060.10 Compliance with a British Standard cannot confer immun
4、ity from legal obligations. This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 May 2012. Amendments issued since publication Date T e x t a f f e c t e dBS ISO 888:2012 ISO 2012 Fasteners Bolts, screws and studs Nominal lengths and thread len
5、gths Fixations Vis, goujons et tiges filetes Longueurs nominales et longueurs filetes INTERNATIONAL STANDARD ISO 888 Second edition 2012-04-15 Reference number ISO 888:2012(E)BS ISO 888:2012ISO 888:2012(E) ii ISO 2012 All rights reserved COPYRIGHT PROTECTED DOCUMENT ISO 2012 All rights reserved. Unl
6、ess otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISOs member body in the country of the requester. ISO
7、copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in SwitzerlandBS ISO 888:2012ISO 888:2012(E) ISO 2012 All rights reserved iii Contents Page Foreword iv 1 Scope 1 2 Normative references . 1 3 Symbols . 1
8、 4 Position of lengths and thread lengths . 1 4.1 General . 1 4.2 Bolts and screws . 2 4.3 Headless screws and set screws 3 4.4 Studs and similar fasteners 3 5 Dimensions for lengths . 5 6 Dimensions for thread lengths 6BS ISO 888:2012ISO 888:2012(E) Foreword ISO (the International Organization for
9、Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the r
10、ight to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. Internation
11、al Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as
12、 an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. IS
13、O 888 was prepared by Technical Committee ISO/TC 2, Fasteners, Subcommittee SC 7, Reference standards. This second edition cancels and replaces the first edition (ISO 888:1976), which has been technically revised. iv ISO 2012 All rights reservedBS ISO 888:2012INTERNATIONAL STANDARD ISO 888:2012(E) F
14、asteners Bolts, screws and studs Nominal lengths and thread lengths 1 Scope This International Standard specifies lengths and thread lengths for bolts, screws and studs for use in appropriate product standards and other relevant documents, e.g. for parts per drawing. It applies to bolts, screws and
15、studs with ISO metric screw thread according to ISO 68-1. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (inc
16、luding any amendments) applies. ISO 68-1, ISO general purpose screw threads Basic profile Part 1: Metric screw threads ISO 225, Fasteners Bolts, screws, studs and nuts Symbols and descriptions of dimensions ISO 4753, Fasteners Ends of parts with external ISO metric thread ISO 4759-1, Tolerances for
17、fasteners Part 1: Bolts, screws, studs and nuts Product grades A, B and C 3 Symbols b thread length b 1thread length of one end for double-end stud b 2thread length of the other end for double-end stud b mthread length of the stud metal end d basic major diameter (nominal diameter) of the thread l n
18、ominal length (of the bolt, screw or stud) l gdistance from the bearing face to the first full form (full profile) thread (bolt), as specified in ISO 225 l slength of the unthreaded shank P pitch of the thread 4 Position of lengths and thread lengths 4.1 General The nominal length, l, and the thread
19、 length, b, features for bolts, screws and studs are specified in ISO 225. Points for bolts and screws are usually included in the length and thread length, except for the pilot point; they are specified in ISO 4753. ISO 2012 All rights reserved 1BS ISO 888:2012ISO 888:2012(E) 4.2 Bolts and screws F
20、or bolts and screws with effective bearing surface perpendicular to the axis, the length shall be defined from the bearing face to the end of the bolt or screw; see Figure 1. Figure 1 Length for bolts and screws with effective bearing surface perpendicular to the axis For flat countersunk bolts and
21、screws, the length shall be defined from the upper edge of the head to the end of the bolt or screw; see Figure 2. Figure 2 Length for bolts and screws with flat countersunk head For raised countersunk bolts and screws, the length shall be defined from the theoretical intersection of the top surface
22、 of the head with the head diameter to the end of the bolt or screw; see Figure 3. Figure 3 Length for bolts and screws with raised countersunk head For concave bearing surfaces, serrated bearing surface and similar, the length shall be defined from the effective bearing plane of the bearing face to
23、 the end of the bolt or screw; see Figures 4 and 5. 2 ISO 2012 All rights reservedBS ISO 888:2012ISO 888:2012(E) Figure 4 Length for bolts and screws with concave bearing surface Figure 5 Length for bolts and screws with serrated bearing surface 4.3 Headless screws and set screws For headless screws
24、 and set screws, the length shall be defined from one extreme end to the other; see Figures 6 and 7. Figure 6 Length for headless screws with shank Figure 7 Length for set screws 4.4 Studs and similar fasteners For partially threaded studs (double-end studs), the length shall be defined from the thr
25、ead run-out at the metal end to the end of the stud at the nut end; see Figure 8. NOTE The thread length of the stud metal end, b m , according to ISO 225, is not within the scope of this International Standard. ISO 2012 All rights reserved 3BS ISO 888:2012ISO 888:2012(E) Key 1 stud metal end 2 nut
26、end Figure 8 Length for partially threaded studs (two threaded ends/shanks) For tie rods (double-end studs with right- and left-hand threads/tensioning studs), for partially threaded studs (single-end stud), for totally threaded studs with points (chamfer or flat) and totally threaded studs (threade
27、d rods/studding), the length shall be defined from one extreme end to the other; see Figures 9 to 12. Figure 9 Length for tie rod Figure 10 Length for partially threaded studs (single-end stud) Figure 11 Length for totally threaded studs (continuous thread) Figure 12 Length for totally threaded stud
28、s (threaded rods) 4 ISO 2012 All rights reservedBS ISO 888:2012ISO 888:2012(E) 5 Dimensions for lengths Dimensions for the lengths are specified in Table 1. Table 1 Lengths for ISO metric bolts, screws and studs Dimensions in millimetresProduct grade Product gradeA B C A B C l l min l max l min l ma
29、x l min l maxl l min l max l min l max l min l max 2 1,80 2,20 (85) 84,30 85,70 83,25 86,75 83,25 86,75 (2,5) 2,30 2,70 90 89,30 90,70 88,25 91,75 88,25 91,75 3 2,80 3,20 (95) 94,30 95,70 93,25 96,75 93,25 96,75 4 3,76 4,24 100 99,30 100,70 98,25 101,75 98,25 101,75 5 4,76 5,24 (105) 104,30 105,70 1
30、03,25 106,75 103,25 106,75 6 5,76 6,24 110 109,30 110,70 108,25 111,75 108,25 111,75 (7) 6,71 7,29 (115) 114,30 115,70 113,25 116,75 113,25 116,75 8 7,71 8,29 120 119,30 120,70 118,25 121,75 118,25 121,75 (9) 8,71 9,29 (125) 124,20 125,80 123,00 127,00 123,00 127,00 10 9,71 10,29 9,25 10,75 9,25 10,
31、75 130 129,20 130,80 128,00 132,00 128,00 132,00 (11) 10,65 11,35 10,10 11,90 10,10 11,90 140 139,20 140,80 138,00 142,00 138,00 142,00 12 11,65 12,35 11,10 12,90 11,10 12,90 150 149,20 150,80 148,00 152,00 148,00 152,00 (14) 13,65 14,35 13,10 14,90 13,10 14,90 160 159,20 160,80 158,00 162,00 156,00
32、 164,00 16 15,65 16,35 15,10 16,90 15,10 16,90 (170) 169,20 170,80 168,00 172,00 166,00 174,00 (18) 17,65 18,35 17,10 18,90 17,10 18,90 180 179,20 180,80 178,00 182,00 176,00 184,00 20 19,58 20,42 18,95 21,05 18,95 21,05 (190) 189,10 190,90 187,70 192,30 185,40 194,60 (22) 21,58 22,42 20,95 23,05 20
33、,95 23,05 200 199,10 200,90 197,70 202,30 195,40 204,60 25 24,58 25,42 23,95 26,05 23,95 26,05 220 219,10 220,90 217,70 222,30 215,40 224,60 (28) 27,58 28,42 26,95 29,05 26,95 29,05 240 239,10 240,90 237,70 242,30 235,40 244,60 30 29,58 30,42 28,95 31,05 28,95 31,05 260 257,40 262,60 254,80 265,20 (
34、32) 31,50 32,50 30,75 33,25 30,75 33,25 280 277,40 282,60 274,80 285,20 35 34,50 35,50 33,75 36,25 33,75 36,25 300 297,40 302,60 294,80 305,20 (38) 37,50 38,50 36,75 39,25 36,75 39,25 320 317,15 322,85 314,30 325,70 40 39,50 40,50 38,75 41,25 38,75 41,25 340 337,15 342,85 334,30 345,70 45 44,50 45,5
35、0 43,75 46,25 43,75 46,25 360 357,15 362,85 354,30 365,70 50 49,50 50,50 48,75 51,25 48,75 51,25 380 377,15 382,85 374,30 385,70 55 54,40 55,60 53,50 56,50 53,50 56,50 400 397,15 402,85 394,30 405,70 60 59,40 60,60 58,50 61,50 58,50 61,50 420 416,85 423,15 413,70 426,30 65 64,40 65,60 63,50 66,50 63
36、,50 66,50 440 436,85 443,15 433,70 446,30 70 69,40 70,60 68,50 71,50 68,50 71,50 460 456,85 463,15 453,70 466,30 (75) 74,40 75,60 73,50 76,50 73,50 76,50 480 476,85 483,15 473,70 486,30 80 79,40 80,60 78,50 81,50 78,50 81,50 500 496,85 503,15 493,70 506,30 Nominal lengths in parentheses (brackets) s
37、hould be avoided, if possible. Tolerances for length are calculated in accordance with ISO 4759-1. ISO 2012 All rights reserved 5BS ISO 888:2012ISO 888:2012(E) 6 Dimensions for thread lengths Unless otherwise specified in a product standard, dimensions for thread lengths, b (see Table 2), shall be c
38、alculated as follows: for l 125 mm: b = 2d + 6 mm for 125 mm 200 mm: b = 2d + 25 mm When the calculation for shorter bolts results in a shank (unthreaded portion) of length 0,5d, the bolt should be fully threaded. Table 2 Thread lengths for ISO metric bolts, screws and studs Dimensions in millimetre
39、s Thread diameter d 1,6 2 2,5 3 4 5 6 8 10 12 (14) 16 18 20 22 Thread length b l 125 9 10 11 12 14 16 18 22 26 30 34 38 42 46 50 125 200 57 61 65 69 Thread diameter d 24 27 30 33 36 39 42 45 48 52 56 60 64 68 72 Thread length b l 125 54 60 66 72 78 84 90 96 102 125 200 73 79 85 91 97 103 109 115 121
40、 129 137 145 153 161 169 Thread diameter d 76 80 85 90 95 100 105 110 115 120 125 130 140 150 160 Thread length b l 125 125 200 177 185 195 205 215 225 235 245 255 265 275 285 305 325 345 Tolerances for thread lengths are specified in ISO 4759-1 as follows: a) for bolts and screws with drives (e.g.
41、hexagon head, hexagon head with flange, hexagon socket head cap, hexalobular cylindrical head, cup head square neck, hexagon or hexalobular countersunk head bolts and similar bolts specified in ISO 225), the tolerances are expressed in terms of l gand l s , and are specified in product standards acc
42、ording to the following: l g,max= l nom b l s,min= l g,max 5P b) for slotted or recessed screws and similar screws (e.g. pan head, cheese head, countersunk head specified in ISO 225) and studs, the tolerance for b is P . 6 ISO 2012 All rights reservedBS ISO 888:2012BS ISO 888:2012 ISO 888:2012(E) IS
43、O 2012 All rights reserved ICS 21.060.10 Price based on 6 pagesThis page deliberately left blankBSI is the independent national body responsible for preparing British Standards and other standards-related publications, information and services. It presents the UK view on standards in Europe and at t
44、he international level. BSI is incorporated by Royal Charter. British Standards and other standardisation products are published by BSI Standards Limited. British Standards Institution (BSI) raising standards worldwide BSI 389 Chiswick High Road London W4 4AL UK Te l + 4 4 ( 0 ) 2 0 8 9 9 6 9 0 0 1
45、Fax +44 (0)20 8996 7001 Revisions British Standards and PASs are periodically updated by amendment or revision. Users of British Standards and PASs should make sure that they possess the latest amendments or editions. It is the constant aim of BSI to improve the quality of our products and services
46、. We would be grateful if anyone finding an inaccuracy or ambiguity while using British Standards would inform the Secretary of the technical committee responsible, the identity of which can be found on the inside front cover. S i m i l a r y f o r P A S s , p l e a s e n o t i f y B S I C u s t o m
47、 e r S e r v i c e s . Te l : + 4 4 ( 0 ) 2 0 8 9 9 6 9 0 0 1 F a x : + 4 4 ( 0 ) 2 0 8 9 9 6 7 0 0 1 BSI offers BSI Subscribing Members an individual updating service called PLUS which ensures that subscribers automatically receive the latest editions of British Standards and PASs. Te l : + 4 4 ( 0
48、 ) 2 0 8 9 9 6 7 6 6 9 F a x : + 4 4 ( 0 ) 2 0 8 9 9 6 7 0 0 1 Email: Buying standards Yo u m a y b u y P D F a n d h a rd c o p y v e r s i o n s o f s t a n d a rd s d i re c t l y u s i n g a credit card from the BSI Shop on the website In addition all orders for BSI, international and foreign standards publications can be addressed to BSI Customer Services. Te l : + 4 4 ( 0 ) 2 0 8 9 9 6 9 0 0 1 F a x : + 4 4 ( 0 ) 2 0 8 9 9 6 7 0 0 1 Email: In response to orders for internatio
