ISO INTERNATIONAL STANDARD 2039-2 Second edition 1987-07-15 INTERNATIONALORGANIZATION FOR STANDARDIZATION ORGANISATION INTERNATIONALE DE NORMALISATION MEKAYHAPOAHAR OPIAHW3ALMR IO CTAHAAPTW3ALMM Plastics - Determination of hardness. Part 2: Rockwellhardness Plastiques - Determination de la durete --- Partie2:DureteRockwell Reference number ISO 2039-2; 1987 (B) 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 bodyinterestedinasubjectforwhichatechnicalcommitteehasbeenestablishedhas the right to be represented on that committee. International organizations, govern- mental and non-governmental, in liaison with iso, also take part in the work. DraftInternational Standardsadopted bythetechnical committees are circulated to the member bodies for approval before their acceptance as International Standards by the Iso Council. They are approved in accordance with IsO procedures requiring at least 75 % approval by the member bodies voting. International Standard ISO2039-2waspreparedbyTechnical CommitteeISO/TC61, Plastics. This second edition cancels and replaces the first edition (iS0 2039-2: 1981), of which it constitutes a minor revision. Users should note that all International Standards undergo revision from time to time and that any reference made herein to any other International Standard implies its latest edition, unless otherwise stated. @International Organization forStandardization,1987 Printed in Switzerland ISO2039-2:1987(E) INTERNATIONALSTANDARD Plastics - Determination of hardness Part 2: Rockwell hardness 1Scopeandfield of application and then followed by a return to the same minor load, all at specified limits for times of loading. The actual measurement is based on the total depth of penetration, minus the elastic 1.1This part of IS0 2039 specifies a method for determining the indentation hardness of plastics by means of the Rockwell recoveryafterafixedtimefollowingremovalofthemajorload, hardness tester using the Rockwell M, L and R hardness scales. minus the penetration resulting from the minor load. The Rockwell hardness number is derived from the net increase in depth of impression as the load on an indentor is increased 1.2ARockwellhardnessnumberisdirectlyrelatedtothein- froma fixed minorload to a major ioad and then returned to the dentation hardness of a plastic material; the higher the same minor load. Rockwell hardness number, the harder the material. Due to a 3.2 Each Rockwell hardness scale division represents two different Rockwell hardness numbers of different scales 0,002 mm vertical movement of the indentor. In practice, the maybeobtainedonthesamematerial,bothofwhichmaybe Rockwell hardness number is derived from the following technically correct. relationship : 1.3 For materials having high creep and recovery, the time- HR = 130 - e factors involved in application of the major and minor loads have a considerable effect on the results of the measurements. where 1.4An alternative method of using the apparatus to give HR is the Rockwell hardness number; hardness ontheRockwell-αhardness scaleis specified inthe e is the depth of impression after removal of the major annexwhichshowshowthisscalemayberelatedtothehard- load, in units of 0,002 mm. ness measurement of iso 2039-1. NOTE - This relationship only holds for the E, M, L and R scales. 2 References 4 Apparatus Iso 48,Rubber,vulcanized -Determination of hardness (Hardnessbetween10and100IRHD).1) 4.1 The apparatus is a standard Rockwell hardness tester Iso291,Plastics-Standardatmospheresforconditioning which comprises essentially and testing. ISo 868, Plastics -Determination of indentation hardness by a rigid frame supporting an adjustable platform fitted means of a durometer (Shore hardness). with a plate at least 50 mm in diameter to support the test spe