ISO INTERNATIONAL STANDARD 7720 Third edition 2012-06-01 Prevailing torque type all-metal hexagon nuts, style 2 — Property class 9 Ecrous hexagonaux autofreinés tout métal, style 2 - Classe de qualité 9 Reference number ISO 7720:2012(E) ISO @ISO2012 ISO 7720:2012(E) COPYRiGHTPROTECTEDDOCUMENT ISO2012 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 ISO 7720:2012(E) Foreword SO(theInternationalOrganizationforStandardization)isaworldwidefederationofnationalstandardsbodies Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/lEc Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards 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. 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 ii