This test method measures the penetration depth of a rigid ball into the surface of a rubber specimen which is then converted to a hardness scale value (IRHD). On the IRHD scale, "0" represents a material having an elastic modulus of zero and 100 represents a material with an immeasurable elastic modulus.
This standard can measure the hardness of vulcanized or thermoplastic rubber. The standard test specimen should be between 8 and 10mm in thickness. Nonstandard specimens can be measured but should be no thinner than 2mm, whereas a micro test can measure specimens between 1.5mm - 2.5mm in thickness.
*Please Note: The information outlined above is to be used as a reference for ASTM D1415 Standard Test Method for Rubber Property-International Hardness and ISO 48 Rubber vulcanized or thermoplastic – Determination of Hardness. Please refer to the appropriate standards agency for full details and the most current revision.