... SELF COLOUR, BLACK,ZP,YZP,H.D.G, DACROMENTMaterials:high quality carbon steel (C1015,C1035,C1045etc)Alloy steel:20 MnTiB ... in the future.9-OEM capacity , for example , can put your mark on the bolt head and so on .1.Materials: ... farmingassembly plantsthe oil refining and drilling industrydefence and commercial ship building industry Torshear Bolts Type High Strength Bolt for buildings and bridges