What is a durometer rating?
Durometer or Shore durometer is a standardized way to measure the hardness of materials like rubber (elastomers) and plastics. Durometer measurement scales range from 0 to 100 but there is no such thing as a durometer unit of measurement.
The above is a simplified graphic representation of a durometer hardness test. The arrows represent the applied load or force the Durometer puts on the material.
Notice that there are significant differences between the shapes of the indenter tips. Type A indenters (left) have a 35° cone angle and Type D indenters (right) have a 30° cone angle. Type A indenters have a “truncated” or flat tip that is 0.79 mm in diameter. Type D indenters have a sharper tip with a rounded end that is 0.1 mm in diameter.
For all materials testing, hardness tests measure the depth of indentation in the material created by a given force using a standardized pressure foot or indenter.
When we refer to Durometer ratings on product specs for any Valor Offroad tires, we always use a Type A Durometer.