cap screw Material: carbon steel, alloy steel Grade: 4.8 6.8 ... 10.9 12.9 Surface Treatment: ZP Blacken HDG Socket cap screw1. Standard: DIN, ISO, IFI, BS, AS2. Grade: ... ,zinc plated CR3+ CR6+., nickel, hot-dipped-galvanized.4. Material: Q195, Q235, 1035.35K,45K 40Gr 35GrMo,42GrMo...5. ... ,zinc plated CR3+ CR6+., nickel, hot-dipped-galvanized.4. Material: Q195, Q235, 1035.35K,45K 40Gr 35GrMo,42GrMo...5. ...