Hardness Shore A vs. Shore D
- 06 Jul, 2021
Shore durometers are used to determine the hardness of a material, for example polmers or rubbers. The two most common scales, using slightly different measurement systems, are the ASTM D2240 type A and type D scales.
Durometer measures the depth of an indentation in the material created by a given force on a standardized presser foot. The difference between Shore A and Shore D is the type of indenter used (see image below).
Figure 1: Comparison between Shore A and Shore D durometer indenters. Taken from Wikipedia "Shore durometer" page.
It is common to use either Shore A or Shore D scales to measure the hardness of a tubing in microfluidics. While Shore A is mostly used for soft-walled materials (silicone, Tygon), Shore D is preferred for harder materials (polymers like PTFE, PEEK, etc.).
Use the following table to convert your Shore A or Shore D value in one or the other scale:
|Shore A||Shore D|