ISO INTERNATIONAL STANDARD 7867-1 Fifth edition 2018-10 Metric series for agricultural, forestry machines and construction tyres - Part 1: Tyre designation, dimensions and marking, and tyre/rim coordination Pneumatiques de la serie millimetrique pour machines agricoles enginsforestiers etengins de construction- Partie 1: Designation dimensionnelle de pneumatiques, cotes, marquagesetcouplespneumatiques-jantes Reference number IS0 7867-1:2018(E) ISO @IS02018 IS0 7867-1:2018(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:[email protected] Website: www.iso.org Published in Switzerland ii IS02018-Allrights reserved IS0 7867-1:2018(E) Contents Page Foreword V 1 Scope 1 2 Normative references. .1 3 Terms and definitions. .1 4 Tyre size designation 2 ２２ 4.1 General. 4.2 Tyre type prefixes 4.3 Nominal section width 3 4.4 Nominal aspect ratio 3 4.5 Tyre construction code 3 4.6 Nominalrimdiametercode 4.7 Tyre type suffixes. 3 5 Marking. 3 5.1 General. 3 5.2 Tyre size designation 4 5.3 Service description. 4 5.4 Additional information 4 5.5 Tyre classification and nomenclature 4 5.6 Tyremaximumpressureforbead seatingpictogram 5 6 Tyre dimensions 5 6.1 55 General 6.2 Calculation of"design tyre"dimensions. 6.2.1 General. 5 6.2.2 Theoretical rim width, Rth 5 6.2.3 Measuring rim width, Rm 6 6.2.4 Design tyre section width, S 6 6.2.5 Design tyre section height, H 6 6.2.6 Design tyre overall diameter, Do 6 6.3 Calculation of"minimumoveralltyredimensions" 7 Minimum overall width, Wmin 6.3.1 7 Minimum overall diameter, Do,min 6.3.2 7 6.4 Calculations of"maximum overall tyre dimensions in service" 7 6.4.1 General. 7 Maximum overall width in service, Wmax 6.4.2 7 6.4.3 Maximum overall diameter in service, Do,max 7 6.5 Coefficientsforcalculationoftyredimensions 7 7 Tyre dimensional data. .8 8 Method of measurement of tyre dimensions .8 9 Tyre and rim coordination .8 9.1 Approved rim widths. 8 9.2 Approved rim contours. 9 10 Tyre parameters for vehicle speed reference .9 Annex A (normative) Tyre design dimensionsand approved rim width codes .10 .17 Annex B (normative) Dimensional guidelines for rim widths and nominal rim diameters AnnexC (informative)Approved rim contoursfor metric agriculturaltractordrivewheel and implements tyres on 5°and 15°tapered rims .19 AnnexD (informative)Rolling circumference (RC),rolling circumference index (RCl)and speedradius index (SRI) values formetric drive wheel tyres .27 @ IS0 2018 - All rights reserved iii