Hardness
Posted on 31/12/2018 Category:
Resistance of rubber to distortion forces. Measured with a Hardness Tester in degrees and based on the resistance to penetration into a standard sized cured rubber sample of a defined indenter under a set load. Three scales are commonly used: IRHD (International Rubber Hardness Degrees), Shore A for standard solid elastomers and Shore D for hard materials over 90° Shore A. IRHD is preferred for most specifications but Shore A is also in widespread use. High values indicate harder materials while low values indicate softer materials. The Shore A and IRHD scales are similar but do not directly correlate.
