BA 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   +10 +10             Change in tensile strength, max. %   -25 -25             Change in ultimate elongation, max. %   -25 -25           B13 Compression set, ASTM D 395, Method B, max. %, 22 h at 70°C     25     25   25 C12 Resistance to ozone, ASTM D 1171, quality retention rating, min. %   100 100 100 100 100 100 100 F17 Low-temperature brittleness, ASTM D 2137, Method A, 9.3.2, nonbrittle after 3 min at -40°C   pass pass pass pass       F19 Low-temperature brittleness, ASTM D 2137, Method A, 9.3.2, nonbrittle after 3 min at -55°C     pass   pass       K11 Adhesion, ASTM D 429, min: Method A, min, MPa     1.4 1.4 1.4 1.4     K21 Adhesion, ASTM D 429, min: Method B, min, kN/m     1.4 1.4 1.4 1.4     K31 Adhesion, bond made after vulcanation     7 B 7 B 7 B       Z (Special requirements). Any special requirements shall be specified in detail, including test methods.   ABasic properties only - no suffix requirements for Grade No. 1. BSuffix K31 indicates that the materials shall be free from surface conditions and compound constituents that are or may become deleterious to cement adhesion.