1、raising standards worldwide NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW BSI Standards Publication Prevailing torque type all-metal hexagon nuts, style 2 Property class 9 BS ISO 7720:2012National foreword This British Standard is the UK implementation of ISO 7720:2012. It s
2、upersedes BS ISO 7720:1997 which is withdrawn. The UK participation in its preparation was entrusted by Technical Committee FME/9, Fasteners, to Subcommittee FME/9/1, Fasteners - Mechanical properties. A list of organizations represented on this committee can be obtained on request to its secretary.
3、 This publication 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 77985 5 ICS 21.060.20 Compliance with a British Standard cannot c
4、onfer immunity from legal obligations. This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 June 2012. Amendments issued since publication Date Text affected BRITISH STANDARD BS ISO 7720:2012 ISO 2012 Prevailing torque type all-metal hexagon nu
5、ts, style 2 Property class 9 crous hexagonaux autofreins tout mtal, style 2 Classe de qualit 9 INTERNATIONAL STANDARD ISO 7720 Third edition 2012-06-01 Reference number ISO 7720:2012(E) BS ISO 7720:2012 ISO 7720:2012(E) ii ISO 2012 All rights reserved COPYRIGHT PROTECTED DOCUMENT ISO 2012 All rights
6、 reserved. Unless 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 r
7、equester. ISO 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 Switzerland BS ISO 7720:2012 ISO 7720:2012(E) Foreword ISO (the International Organization for Standardization) is a worldwide federation
8、 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 right to be represented on that committee.
9、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. International Standards are drafted in accordance wit
10、h 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 an International Standard requires approv
11、al 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. ISO 7720 was prepared by Technical Committee
12、 ISO/TC 2, Fasteners, Subcommittee SC 12, Fasteners with metric internal thread. This third edition cancels and replaces the second edition (ISO 7720:1997), which has been technically revised. ISO 2012 All rights reserved iii BS ISO 7720:2012 Prevailing torque type all-metal hexagon nuts, style 2 Pr
13、operty class 9 1 Scope This International Standard specifies the characteristics of prevailing torque type all-metal hexagon nuts, of style 2, with threads from M5 up to and including M36, in product grade A for threads up to and including M16, and product grade B for threads over M16, and with prop
14、erty class 9. NOTE 1 The dimensions of the nuts, with the exception of the dimensions m wand h max , correspond to those given in ISO 4033. NOTE 2 Nuts of property classes 5, 8, 10 and 12 are dealt with in ISO 7042. If other specifications are required, they can be selected from existing Internation
15、al Standards, for example ISO 261, ISO 724, ISO 898-2, ISO 965-2, ISO 2320 and ISO 4759-1. 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 editio
16、n of the referenced document (including any amendments) applies. ISO 225, Fasteners Bolts, screws, studs and nuts Symbols and descriptions of dimensions ISO 261, ISO general purpose metric screw threads General plan ISO 724, ISO general-purpose metric screw threads Basic dimensions ISO 898-2, Mechan
17、ical properties of fasteners made of carbon steel and alloy steel Part 2: Nuts with specified property classes Coarse thread and fine pitch thread ISO 965-2, ISO general purpose metric screw threads Tolerances Part 2: Limits of sizes for general purpose external and internal screw threads Medium qua
18、lity ISO 2320, Prevailing torque type steel hexagon nuts Mechanical and performance properties ISO 3269, Fasteners Acceptance inspection ISO 4042, Fasteners Electroplated coatings ISO 4759-1, Tolerances for fasteners Part 1: Bolts, screws, studs and nuts Product grades A, B and C ISO 6157-2, Fastene
19、rs Surface discontinuities Part 2: Nuts ISO 8992, Fasteners General requirements for bolts, screws, studs and nuts ISO 10683, Fasteners Non-electrolytically applied zinc flake coatings INTERNATIONAL STANDARD ISO 7720:2012(E) ISO 2012 All rights reserved 1 BS ISO 7720:2012 ISO 7720:2012(E) 3 Dimensio
20、ns For dimensions, see Figure 1 and Table 1. Symbols and descriptions of dimensions are specified in ISO 225. aPrevailing torque element; shape is at the discretion of the manufacturer. b = 15 to 30. c = 90 to 120. Figure 1 Table 1 Dimensions Dimensions in millimetres Thread D M5 M6 M8 M10 M12 (M14)
21、 a M16 M20 M24 M30 M36 P b0,8 1 1,25 1,5 1,75 2 2 2,5 3 3,5 4d a max. 5,75 6,75 8,75 10,80 13,00 15,10 17,30 21,60 25,90 32,40 38,90 min. 5,00 6,00 8,00 10,00 12,00 14,00 16,00 20,00 24,00 30,00 36,00 d w min. 6,88 8,88 11,63 14,63 16,63 19,64 22,49 27,70 33,25 42,75 51,11 e min. 8,79 11,05 14,38 17
22、,77 20,03 23,36 26,75 32,95 39,55 50,85 60,79h max. 5,30 6,70 8,00 10,50 13,30 15,40 17,90 21,80 26,40 31,80 38,50 min. 4,80 5,40 7,14 8,94 11,57 13,40 15,70 19,00 22,60 27,30 33,10 m w c min. 3,84 4,32 5,71 7,15 9,26 10,70 12,60 15,20 18,10 21,80 26,50 s max. 8,00 10,00 13,00 16,00 18,00 21,00 24,0
23、0 30,00 36,00 46,00 55,00min. 7,78 9,78 12,73 15,73 17,73 20,67 23,67 29,16 35,00 45,00 53,80 aThe size in parentheses (brackets) should be avoided, if possible. bP is the pitch of the thread. cMinimum wrenching height. 2 ISO 2012 All rights reserved BS ISO 7720:2012 ISO 7720:2012(E) 4 Requirements
24、and reference International Standards See Table 2. Table 2 Requirements and reference International Standards Material Steel General requirements International Standard ISO 8992 Thread Tolerance class 6H International Standards ISO 261, ISO 724, ISO 965-2 Mechanical and performance properties Proper
25、ty class 9 International Standard ISO 898-2, ISO 2320 Tolerance Product grade For D M16: A For D M16: B International Standard ISO 4759-1 Finish Coating As processed Requirements for electroplating are specified in ISO 4042. Requirements for non-electrolytically applied zinc flake coatings are speci
26、fied in ISO 10683. Additional requirements or other finishes or coatings shall be agreed between the supplier and the purchaser. Surface integrity Limits for surface discontinuities are specified in ISO 6157-2. Acceptability Acceptance inspection is specified in ISO 3269. 5 Designation EXAMPLE A pre
27、vailing torque type all-metal hexagon nut, of style 2, with thread M12 and property class 9 is designated as follows: Prevailing torque type hexagon nut ISO 7720 - M12 - 9 ISO 2012 All rights reserved 3 BS ISO 7720:2012 ISO 7720:2012(E) Bibliography 1 ISO 4033, Hexagon nuts, style 2 Product grades A
28、 and B 2 ISO 7042, Prevailing torque type all-metal hexagon nuts, style 2 Property classes 5, 8, 10 and 12 4 ISO 2012 All rights reserved BS ISO 7720:2012This page deliberately left blankThis page deliberately left blankBSI is the independent national body responsible for preparing British Standards
29、 and other standards-related publications, information and services. It presents the UK view on standards in Europe and at the international level. BSI is incorporated by Royal Charter. British Standards and other standardisation products are published by BSI Standards Limited. British Standards Ins
30、titution (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 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
31、possess the latest amendments or editions. It is the constant aim of BSI to improve the quality of our products and services. 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 identit
32、y 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 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 P
33、LUS which ensures that subscribers automatically receive the latest editions of British Standards and PASs. Te l : + 4 4 ( 0 ) 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
34、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 f
35、or international standards, BSI will supply the British Standard implementation of the relevant international standard, unless otherwise requested. Information on standards BSI provides a wide range of information on national, European and international standards through its Knowledge Centre. Te l :
36、 + 4 4 ( 0 ) 2 0 8 9 9 6 7 0 0 4 F a x : + 4 4 ( 0 ) 2 0 8 9 9 6 7 0 0 5 Email: BSI Subscribing Members are kept up to date with standards developments and receive substantial discounts on the purchase price of standards. For details of these and other benefits contact Membership Administration. Te
37、 l : + 4 4 ( 0 ) 2 0 8 9 9 6 7 0 0 2 F a x : + 4 4 ( 0 ) 2 0 8 9 9 6 7 0 0 1 Email: Information regarding online access to British Standards and PASs via British Standards Online can be found at Further information about British Standards is available on the BSI website at www.bsi- Copyright All t
38、he data, software and documentation set out in all British Standards and other BSI publications are the property of and copyrighted by BSI, or some person or entity that own copyright in the information used (such as the international standardisation bodies) has formally licensed such information to
39、 BSI for commerical publication and use. Except as permitted under the Copyright, Designs and Patents Act 1988 no extract may be reproduced, stored in a retrieval system or transmitted in any form or by any means electronic, photocopying, recording or otherwise without prior written permission from
40、BSI. This does not preclude the free use, in the course of implementing the standard, of necessary details such as symbols, and size, type or grade designations. If these details are to be used for any other purpose than implementation then the prior written permission of BSI must be obtained. Details and advice can be obtained from the Copyright & Licensing Department. Te l : + 4 4 ( 0 ) 2 0 8 9 9 6 7 0 7 0 Email:
