scope:

This International Standard specifies a method for the determination of the indentation hardness of plastics and ebonite by means of durometers of two types: durometer type A is used for softer materials and durometer type D for harder materials. The method permits measurement either of the initial indentation or of the indentation after a specified period of time, or both. This method is an empirical test intended primarily for control purposes. No simple relationship exists between indentation hardness determined by this method and any fundamental property of the material tested. For specification purposes, it is recommended that ISO 48, Vulcanized rubbers - Determination of hardness (hardness between 30 and 85 IRHD), should be used for softer materials.