1、BRITISH STANDARD AEROSPACE SERIES CONFIRMED AUGUST 1985 BS S 158: 1977 Specification for 1% chromium- molybdenum steel bars forthe manufacture of forged bolts and forged nuts UDC 629.7:621.882:669.152628:669.14.018.26BSS158:1977 This British Standard, having been prepared under the directionof the A
2、erospace Standards Committee, was published under the authority ofthe Executive Board on 31May1977 BSI 01-2000 The following BSI references relate to the work on this standard: Committee reference ACE/15 Draft for comment 76/73898 DC ISBN 0 580 09813 0 A British Standard does not purport to include
3、all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i a
4、nd ii, page 1 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Amendments issued since publication Amd. No. Date of issue CommentsBSS158:1977 BSI 01-2000 i Contents
5、 Page 1 Inspection and testing procedure 1 2 Manufacture 1 3 Chemical composition 1 4 Surface dressing 1 5 Condition 1 6 Heat treatment 1 7 Mechanical properties 1 8 Grain size 1ii blankBSS158:1977 BSI 01-2000 1 NOTEThe requirements for the finished bolts and nuts are given in the relevant specifica
6、tions for those products, such as those in the “A” series of British Standards. 1 Inspection and testing procedure 1.1 General. This British Standard shall be used in conjunction with sections1 and9 of the latest issue of BSS100. 1.2 Sulphur printing or deep etching tests. One sample shall be taken
7、from each ingot for sulphur printing or deep etching tests. 1.3 Ultrasonic examination. Billets shall be subjected to ultrasonic examination. 2 Manufacture The material shall be manufactured by an electric process. 3 Chemical composition The steel shall contain: 4 Surface dressing The material shall
8、 be overall dressed. 5 Condition 5.1 Bar in straight lengths. Bar delivered in straight lengths shall be supplied annealed and either cold drawn or centreless ground. 5.2 Bar in coil. Bar delivered in coil shall be supplied spheroidized, cold drawn and suitably coated for cold forging. 6 Heat treatm
9、ent The final heat treatment applicable to bolts and nuts made from this material and to their representative test samples shall consist of the following. a) Hardening. Heat at a temperature of870 10 C, followed by cooling in oil. b) Tempering. Heat uniformly at a temperature between450 C and660 C,
10、followed by cooling in air. 7 Mechanical properties 7.1 Hardening test. The hardness shall be not less than500HV. 7.2 Tests in the condition of supply. Material delivered in the condition specified in5.1 or5.2, as appropriate, shall comply with the following requirements. 8 Grain size The grain size
11、 shall be determined in accordance with BS4490 “Method for the determination of the austenitic grain size of steel”, method3 or method5. The grain size shall be no.5 or finer and no grain shall be coarser than no.3. Element % min. max. Carbon 0.22 0.29 Silicon 0.15 0.35 Manganese 0.50 0.80 Phosphoru
12、s 0.020 Sulphur 0.015 Chromium 0.9 1.2 Molybdenum 0.15 0.25 Nickel 0.30 Bar in straight lengths Bar in coil Tensile strength (max.) (MPa) 750 650 or Hardness (max.) 217 HB NOTEMPa = N/mm 2 . Information on SI units is given inBS3763 “The International System of units (SI)” and BS350 “Conversion fact
13、ors and tables”.BS S 158: 1977 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the independent national body responsible for preparing BritishStandards. It presents the UK view on standards in Europe and at the international level. It is incorporated by Royal Charter.
14、Revisions BritishStandards are updated by amendment or revision. Users of BritishStandards 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. We would be grateful if anyone finding an inaccuracy or
15、ambiguity while using this BritishStandard would inform the Secretary of the technical committee responsible, the identity of which can be found on the inside front cover. Tel:02089969000. Fax:02089967400. BSI offers members an individual updating service called PLUS which ensures that subscribers a
16、utomatically receive the latest editions of standards. Buying standards Orders for all BSI, international and foreign standards publications should be addressed to Customer Services. Tel:02089969001. Fax:02089967001. In response to orders for international standards, it is BSI policy to supply the B
17、SI implementation of those that have been published as BritishStandards, unless otherwise requested. Information on standards BSI provides a wide range of information on national, European and international standards through its Library and its Technical Help to Exporters Service. Various BSI electr
18、onic information services are also available which give details on all its products and services. Contact the Information Centre. Tel:02089967111. Fax:02089967048. Subscribing members of BSI are kept up to date with standards developments and receive substantial discounts on the purchase price of st
19、andards. For details of these and other benefits contact Membership Administration. Tel:02089967002. Fax:02089967001. Copyright Copyright subsists in all BSI publications. BSI also holds the copyright, in the UK, of the publications of the international standardization bodies. Except as permitted un
20、der 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 BSI. This does not preclude the free use, in the course of impl
21、ementing 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. If permission is granted, the terms may include royalty payments or a licensing agreement. Details and advice can be obtained from the Copyright Manager. Tel:02089967070.
