ISO/TS TECHNICAL SPECIFICATION 4949 Second edition 2016-11-01 Steel names based on letter symbols Désignations des aciers fondees sur des lettres symboles Reference number ISO/TS 4949:2016(E) ISO International Organization for Standardization @IS02016 mitted without license from IHS IS0/TS 4949:2016(E) COPYRIGHT PROTECTED DOCUMENT IS0 2016, Published in Switzerland All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISO's member body in the country of the requester. ISO copyright office Ch. de Blandonnet 8 . CP 401 CH-1214 Vernier, Geneva, Switzerland Tel. +41 22 749 01 11 Fax +41 22 749 09 47 copyright@iso.org www.iso.org networking permited without license from IHS IS0/TS 4949:2016(E) Contents Page Foreword ..iv 1 Scope 1 2 Normative references .1 3 Terms and definitions ..1 4 Principles .1 4.1 A unique steel name .1 4.2 Formulation of steel names. 1 4.3 Allocation of steel names. 1 5 Reference to product standards ..1 6 Classification of steel names .2 7 Structure of steel names. .2 7.1 Initial symbol for steel castings ..2 7.2 Steels designated according to their application and mechanical or physical properties (group 1) ..2 7.3 Steels designated according to chemical composition (group 2) 4 7.3.1 Non-alloy steels (except free-cutting steels) with an average manganese content < 1 % (sub-group 2.1). 4 7.3.2 Non-alloy steels with an average manganese content ≥ 1 %, non-alloy free-cutting steels and alloy steels (except high speed steels) where the average content, by mass, of every alloying element is < 5 % (sub-group 2.2). 7.3.3 Alloy steels (except high speed steels) where the average content by mass of at least one alloying element is ≥ 5 % (sub-group 2.3) 5 7.3.4 High speed steel (sub-group 2.4) ..5 8 Additional symbols .5 Annex A (normative) Additional symbols indicating special requirements ..6 1 Annex B (normative) Additional symbols indicating type of coating. Annex C (normative) Additional symbols indicating treatment condition ..8 Bibliography 9 ii thout license from IHS