Hardness Testing

Shore hardness testing is widely used for rubber and plastics. A shaped steel indenter is pressed perpendicularly into the specimen under a test force. When the presser foot fully contacts the surface, the indenter's protrusion relative to the foot gives the penetration depth. A mechanical or electronic measuring system converts that depth into a Shore hardness value. Deeper penetration indicates a softer material.

Product testing follows ASTM D2240 for Shore hardness.

Specimens are generally 6.4 mm thick. Multiple layers may be stacked to reach the required thickness, although a single specimen is preferred.

A durometer is used for measurement. Shore A and Shore D are common scales: Shore A is used for softer specimens and Shore D for harder specimens.