ISO INTERNATIONAL STANDARD 11891 First edition 2012-04-15 Hot formed helical compression springs Technical specifications Ressorts de compression hélicoidaux formés a chaud - Spécifications techniques Reference number ISO 11891:2012(E) ISO @ISO2012 No reproduction or networking permitted without license from IHS Not for Resale ISO 11891:2012(E) COPYRiGHTPROTECTEDDOCUMENT ISO 2012 All rights 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 ISO's member body in the country of the requester. ISO copyright office Case postale 56 · CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyright@iso.org Web www.iso.org Published in Switzerland ISO 2012-All rights reserved or networking permited withoutlicense from IHS Not for Resale ISO 11891:2012(E) Contents Page Foreword .iv 1 Scope 2 Normative references 3 Terms, definitions and symbols 3.1 Terms and definitions. 3.2 Symbols and units .. 4 4.1 Adoption of material. 4.2 Diameter and tolerance of bars 5 Spring construction. 5.1 Direction of helix 5.2 Types of coil end. 3 6 Spring characteristics. 3 6.1 General 6.2 Length at a specified load. 6.3 Load at a specified length.. 3 6.4 Spring rate.... 7 Tolerances of spring dimensions and characteristics 7.1 7.2 Freelength 7.3 Diameter of coils.. 7.4 Total coils 7.5 Perpendicularity.. 7.6 Parallelism.... 7.7 Irregularity of pitch. 7.8 Solid length... 5 7.9 Tolerances on spring characteristics Requirements for manufacturing 6 8.1 Heat treatment 6 8.2 Hardness. 8.3 Decarburization. 8.4 Grain size.... 6 8.5 Surface conditions 8.6 End surface machining 8.7 Shot peening. 8.8 Setting (presetting) 6 8.9 Surface protection. 6 9 Test methods 6 9.1 General 6 9.2 Spring characteristics. 9.3 Dimensions and shapes 9.4 Surface conditions 8 9.5 Hardness. 9.6 Decarburization. 9.7 Grain size 8 9.8 Shot peening. 9.9 Surface protection. Bibliography 9 ili ted without licensefrom IHS Not for Resale