ISO INTERNATIONAL 4156-3 STANDARD Second edition 2021-02 Straight cylindrical involute splines - Metric module, side fit - Part 3: Inspection Cannelures cylindriques droites a flancs en développante - Module métrique,acentragesurflancs- Partie 3:Verification Referencenumber IS0 4156-3:2021(E) ISO @IS0 2021 IS04156-3:2021(E) COPYRIGHTPROTECTEDDOCUMENT IS02021 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 401 · Ch.de Blandonnet 8 CH-1214 Vernier,Geneva Phone: +41 22 749 0111 Email:[email protected] Website:www.iso.org Published in Switzerland ii IS02021-Allrightsreserved IS04156-3:2021(E) Contents Page Foreword Introduction. ..vi 1 Scope. .1 2 Normative references .1 3 Terms and definitions 4 Symbols and abbreviated terms. .1 5 Reference conditions .4 6 Qualityfeatures 6.1 General 4 6.2 Size 4 6.2.1 Actual size 6.2.2 Effective size 4 6.3 Location. 5 6.4 Form. 5 7 Methods of inspection 5 7.1 Size. 5 7.1.1 General methods 5 7.1.2 Choiceofmeasuringinstrument. 5 7.1.3 Actual size. 5 7.1.4 Effectivesize 8 7.2 8 Location 7.2.1 General. 8 7.2.2 Choice of the method of inspection of location 8 7.2.3 Effective axis using mating part. 9 7.2.4 Actual pitchcylinderaxis 9 7.2.5 Calculation with Fourier analysis 9 7.2.6 Spline clamping system 10 7.3 Form. 10 8 Measurements withballs orpins. .10 8.1 General. 10 8.2 Selection ofballs or pins 11 8.3 Use and marking of pins 11 8.4 Statistical actual tolerancelimit LsTA .11 8.4.1 General. 11 8.4.2 Acceptance of parts according to the statistical actual tolerance limit LsTA .12 13 8.4.3 Examples. 8.5 Calculation of ball or pin diameter (DRe or DRi) 13 8.5.1 External spline. 13 8.5.2 Internal spline. 14 8.6 Calculation of dimensionsfor ball or pin inspection (part andgauge inspection) 15 8.6.1 Exactcalculation 15 8.6.2 Approximationfactor. 18 9 Measurementoverkteeth-External splines (W) .21 9.1 Calculation of W. 21 9.2 Choice of k 21 10 Gauges. .23 10.1 .23 Generalities 10.1.1 Conditions of use of gauges. 23 10.1.2 Limitingdimensions ofuseforgauges. 23 10.1.3 Handles of spline gauges 23 @IS0 2021- All rights reserved ii