ISO INTERNATIONAL STANDARD 19843 First edition 2018-10 Rolling bearings Ceramic bearing balls - Determination of strength by notched ball test Roulements-Billes en ceramique-Déterminationde larésistance par test sur bille rainuree Reference number IS0 19843:2018(E) ISO @IS0 2018 IS019843:2018(E) COPYRIGHTPROTECTEDDOCUMENT IS02018 All rights reserved. Unless otherwise specified, or required in the context of its implementation, 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 CP 40i : Ch. de Blandonnet 8 CH-1214 Vernier, Geneva Phone: +4122.749 0111 Fax: +41 22 749 09 47 Email:copyright@iso.org Website: www.iso.org Published in Switzerland ii IS02018-Allrights reserved IS019843:2018(E) Contents Page Foreword iv Introduction V 1 Scope .1 2 Normativereferences .1 3 Terms and definitions .1 4 Symbols .6 5 Test description .7 6 Equipment and testing devices 7 6.1 Loading device. 7 6.2 Testing machine 8 6.3 Measuring devices. 8 6.3.1 General. 8 6.3.2 Micrometerforexternalmeasurement 8 6.3.3 Mechanical dial gauge 8 6.3.4 Light microscope 8 6.3.5 Measuringgaugeforthedetermination oftheligamentthickness 8 6.4 Grinding machine 9 6.5 Psychrometer 9 6.6 Dryer. .9 7 Preparationofthenotchedball .9 7.1 Number of test pieces n .9 7.2 Diameterdetermination 9 7.3 Preparationofthenotch .10 7.3.1 General. 10 7.3.2 Notch geometry 10 7.4 Cleaning. .11 8 Test procedure .11 8.1 Measurementofnotchparameters 11 8.2 Mechanical testing .13 9 Evaluation .15 10 Potentialuncertainties and deviations .15 11 Testreport ..15 AnnexA(normative)Functiontablesforprefactorf .17 AnnexB (normative)Comparabilityofnotchedball strengthresults .20 AnnexC (informative)V-blocksystemforpreparationofthenotch .24 AnnexD (informative)Positioningaid .26 Annex E (informative) Example of a test report for determination of the notched ball strength....27 AnnexF (normative)Notchrootdamageduetomachining .29 Annex G (informative) Proposed initial testing speed for the cross head. .31 Bibliography .32 @ IS0 2018 - All rights reserved iii