... ,GB Bolt/Screw and non-standard products2. Products: hex bolts, heavy hex bolts/screws, hex cap screws, hex flange screws,Round head bolts, round head square neck ... , tapping screws, machine screws, wood screws, and non-standard products3.Thread: UNC,UNF,UN 4.Grade: DIN:GR4.8,8.8,10 ... in bridges, buildings, machinery, auto, railway ,petrol and other industries Hex head Bolt