Shore durometer test procedures involve measuring a penetration depth to assess a material’s hardness. Named after Albert Shore, this is a value scale that is widely used for testing plastics. In a Shore durometer test, a spring-loaded test pin strikes a specimen and its penetration depth measured.

Shore hardness values are not expressed in a particular dimension but are recorded on a scale of 1 to 100. The softer a material is, the deeper the test pin will penetrate it. Shore A and D methods differ from one another by the shape of the test pin’s spike and the amount of force exerted by the spring on the spike.