Tool parts of screw bit position screwdriver bit drill bit Nonstandard screw driver bits (customized shapes) 1.Material types:Cr-V 6150,8660,S22.Surface treatment:sandblasted, tin-coating, Cu-coating, Ni-coating, Cr-coating, Zn-coating3.Head types:PH, PZ, slot, Torx, square, hex, hex-plus, Z-spanner, Torx hollow, Torx plus, tri-wing4.length:25-300MM5. Special heat-treated6.Different sizes ...