The Shore test, using either the Shore A or Shore D scale, is used for measuring the hardness of rubbers/elastomers and is also commonly used for softer plastics as polyolefins, fluoropolymers, and vinyls. The A scale is used for softer rubbers while the D scale is used for harder ones.
The Shore hardness is measured with an apparatus known as a Durometer. The hardness value is determined by the penetration of the Durometer indenter foot into the sample. The Shore scale ranges from 0 (full penetration) to 100 (no penetration).
The results obtained from this test are a useful measure of relative resistance to indentation of various grades of polymers. However, the Shore Durometer hardness test does not serve well as a predictor of other properties such as strength or resistance to scratches, abrasion, or wear, and should not be used alone for product design specifications.
The most common household item with a Shore hardness rating is propably an in-line roller blade wheel.