The ASTM D2240 standard covers type A, B, C, D, DO, and OO durometers. The most popular durometers are the types A and D. Very soft materials are rated on the Shore OO scale. Rubber and polyurethane are rated on the Shore A scale and hard materials are rated on the Shore D scale.
Type A - Soft Rubber, Elastomers, Waxes, Printing Rollers.
Type OO - Sponge Rubber, Very soft Rubber
This is an extract from D2240-97… so it is not recommended to cross-reference between scales, it should be used for comparisons only.
"...there may be no simple relationship between the results obtained with one type of durometer and those obtained with another type of durometer or other instruments for measuring hardness. This test method is an empirical test intended primarily for control purposes. No simple relationship is known to exist between indentation hardness determined by this method and any fundamental property of the material tested."
The equivalent 'DIN' standard is 'DIN 53505'.
Speedy
"Tell a man there are 300 billion stars in the universe and he'll believe you. Tell him a bench has wet paint on it and he'll have to touch to be sure."
Speedy, boo1, and atad;
Thank you for your valued responses.
Note that the scale conversion chart furnished by boo1 (March 30, 2003) turned out to be reasonably accurate, within the range I was interested. The material that I purchased with the advertised specification of 55-65 Shore OO was measured here with a Shore A durometer tester and achieved 15 - 20 Shore A. This fulfilled our immediate requirements. Thanks again.
