AK MATERIALS   Suffix Requirements Grade 1A Grade 2 Grade 3 Grade 4 Grade 5 Grade 6 Grade 7 Grade 8 A14 Heat Resistance, ASTM D 573, 70 h at 70°C:                   Change in hardness, max. points   +15 +15             Change in tensile strength, max. %   -15 -15             Change in ultimate elongation, max. %   -40 -40           B33 Compression set, ASTM D 395, Method B, max. %, 22 h at 70°C   50 50           EO14 Fluid resistance, ASTM D 471, Oil No. 1, 70 h at 100°C                   Change in tensile strength, max. %   † †             Change in ultimate elongation, max. %   † †             Change in durometer hardness, max. points   † †             Change in volume, max. %   -3 to +5 -3 to +5           EO34 Fluid resistance, ASTM D 471, Oil No. 3, 70 h at 100°C                   Change in tensile strength, max. %   -5 to +10 -5 to +10             Change in ultimate elongation, max. %   -30 -30             Change in durometer hardness, max. points   -50 -50             Change in volume, max. %   † †           F17 Low-temperature brittleness, ASTM D 2137, Method A, 9.3.2, nonbrittle after 3 min at -40°C   pass             Z (Special requirements). Any special requirements shall be specified in detail, including test methods.   ABasic properties only - no suffix requirements for Grade No. 1. † The requirement is applicable, and materials are available having these characteristics, but values have not yet been established