Class 8.8 White zinc plating hex flange washer head screw
Head markings and mechanical properties Head marking Grade, material & condition Nominal size range [mm] Proof strength [MPa] Yield strength (min) [MPa] Tensile strength (min) [MPa] Core hardness [Rockwell] Class 4.6 Low or medium carbon steel 5–100 225 240 400 B67–95 Class 4.8 Low or medium carbon steel; fully or