AK MATERIALS BASIC REQUIREMENTS Durometer Hardness, +-5 Points Tensile Strength, min Mpa psi Ultimate Elognation, min. % Heat Aged, ASTM D 573, 70 h at 70 ° C Oil Immersion, ASTM D 471, No. 3 Oil, 70 h at 70 ° C Compression Set, ASTM D 395, Solid, max. %; 22 h at 70 ° C Available Suffixes Grade Numbers 40 3 435 400       2 50 3 435 400 2 60 5 725 300 2 70 7 1015 250 2 80 7 1015 150 3 90 7 1015 100 3