ISO INTERNATIONAL STANDARD 2320 Fifth edition 2015-12-01 Fasteners Prevailing torque steel nuts Functional properties Fixations - Ecrous autofreinés en acier Caractéristiques fonctionnelles Accessed by UNSW - LIBRARY on 04 Dec 2017 (Document currency not guaranteed when printed) Reference number ISO 2320:2015(E) ISO @IS02015 IS0 2320:2015(E) COPYRIGHT PROTECTEDDOCUMENT @ IS0 2015, Published in Switzerland All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form writtenpermission.Permission canberequestedfromeitherIsOattheaddressbelow orIso'smemberbodyinthecountryof the requester. ISO copyrightoffice Ch. de Blandonnet 8 . CP 401 CH-1214 Vernier, Geneva, Switzerland Tel. +41 22 749 01 11 Fax +41 22 749 09 47 [email protected] www.iso.org i @ IS0 2015 - All rights reserved IS0 2320:2015(E) Contents Page Foreword ..iv 1 Scope .1 2 Normative references ..1 3 Terms and definitions 4 Symbols ..2 5 Thread. ..3 6 Lubrication .3 7 Mechanical properties of prevailing torque nuts 8 Functional requirements for prevailing torque properties .3 9 Test method. .11 9.1 General. 11 9.2 Proof load test. .11 9.3 Prevailing torque test. .11 9.3.1 General. .11 9.3.2 Test apparatus. 12 9.3.3 Test parts .12 9.3.4 Test procedure 13 9.3.5 Test report. .15 Annex A (normative) Temperature influence on prevailing torques of nuts with non- metallic insert .16 Annex B (informative) Principles for the evaluation of the total coefficient of friction, μtot ..17 Annex C (informative) Test clamp force and prevailing torques for prevailing torque nuts M3 and M4 in property classes 8 and 10 .18 Bibliography .20 @ IS0 2015 - All rights reserved ii