Hardness measurement Shore A and Shore D

In hardness measurement according to DIN EN ISO 868, the penetration depth of a spring-loaded pin into the material to be tested is measured. Depending on the materials to be tested, different geometries of the indenters are prescribed.

For the determination of the Shore hardness A, a truncated cone with an end face of 0.79 mm in diameter and an opening angle of 35° is used as the indenter. This measuring method is used for softer samples.

For the Shore hardness D test, a truncated cone with a spherical tip with a radius of 0.1 mm and an opening angle of 30° is used as the indenter. This method is often used for slightly harder and stiffer specimens.

For the test, the specimens are placed on a hard horizontal flat surface and loaded with the gauge for 15 seconds. The Shore hardness obtained can be read directly on the scale of the indicator.

Shore hardness measurement is a frequent test in the quality assurance of thermoplastic elastomers (TPE).