ISO INTERNATIONAL STANDARD 48-2 First edition 2018-08 Rubber, vulcanized or thermoplastic - Determination of hardness Part 2: Hardness between 10 IRHD and 100 IRHD Caoutchouc vulcanisé ou thermoplastique Deétermination de la dureté Partie 2: Dureté comprise entre 10 DIDC et 100 DIDC Reference number IS0 48-2:2018(E) ISO @ IS0 2018 IS0 48-2:2018(E) Contents Page Foreword .iv Introduction V 1 Scope. 1 2 Normative references. ..2 3 Terms and definitions 2 4 Principle 5 Apparatus 3 5.1 General. 3 5.2 Methods N, H, L and M. 5.3 Methods CN, CH, CL and CM, 5.3.1 Cylindrical surfaces of radius greater than 50 mm. 5 5.3.2 Surfaces with double curvature of large radius greater than 50 mm.. 5 5.3.3 Cylindrical surfaces of radius 4 mm to 50 mm or small test pieces with double curvature. 5 5.3.4 Small O-rings and articles of radius of curvature less than 4 mm. 6 Test pieces. 5 6.1 General 6.2 Methods N, H, L and M 6.2.1 General. 6.2.2 Thickness 6.2.3 Lateraldimensions, 6.3 Methods CN, CH, CL and CM. 7 Time interval between forming and testing 8 Conditioning of test pieces. 9 Temperature of test 10 Procedure 11 Number of reading.. 7 12 Expression of results .. .8 13 Precision 14 Testreport. ..10 Annex A (informative) Empirical relationship between indentation and hardness. 12 Annex B (informative) Precision results from interlaboratory test programmes 15 Bibliography. .23 @ IS0 2018 - All rights reserved ili IS0 48-2:2018(E) Foreword Iso (the International Organization for Standardization) is a worldwide federation of national standards bodies (IsO member bodies). The work of preparing International Standards is normally carried out through Iso technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with IsO, also take part in the work. Iso collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization The procedures used to develop this document and those intended for its further maintenance are described in the Iso/IEc Directives, Part 1. In particular, the different approval criteria needed for the different types of IsO documents should be noted, This document was drafted in accordance with the editorial rules of the ISo/IEc Directives, Part 2 (see Wwwiso.org/directives). 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. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the Iso list of patent declarations received (see www.iso.org/patents). Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement. For an explanation of the voluntary nature of standards, the meaning of Iso specific terms and expressions related to conformity assessment, as well as information about IsoO's adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following URL: Wwwwiso.org/iso/foreword.html. This document was prepared by Technical Committee ISo/TC 45, Rubber and rubber products, Subcommittee SC 2, Testing and analysis. This first edition of IS0 48-2 cancels and replaces IS0 48:2010, of which it constitutes a minor revision The changes compared to the previous edition are as follows: a new standard number has been given. in the Introduction, an explanation of the purpose of the grouping work has been added. in Clause 12, an alternative way of expressing results has been added. A list of all parts in the ISO 48 series can be found on the ISO website. Any feedback or questions on this document should be directed to the user's national standards body. A complete listing of these bod