... , galv, Phosphating. Cr3+, black, hardening process3 Head type: Pan head, hex head, round head, hex flange head or customize.4 Packing: Based on customer requirement, usually ... : Bolts, hex head bolts , hexagon head screw , mushroom head squre neck bolts , t- head bolts , wing screw , screw pan head slotted screws , cheese head slotted screws ...