Durometer Hardness Ranges
Shore “A” indicates the softer durometers, while Shore “D” represents the more rigid durometers. Durometer hardness values are nominal with a ± range of (4) points. All testing per ASTM D 2240-86.
Below in the example; the hardness of plastic sheet on the Shore A scale compared to the Shore D scale.
Shore A Relationship to Shore D Nominal Durometer Values