... 6Material: Brass, Bronze, Carton steel(low/medium/high carbon steel) Stainless steel, Aluminum alloy,Surface Treatment: ... Screw bolts/Studs, Nuts, Tapping screws, Wooden screws, Washers/Gaskets, Check rings, Pins, Rivets and etc. 2. by head ... types Flat, Oval, Binding, Pan, Round, Truss, Button, PF, Pan washer, Cheese, Countersunk, ... .com.cn Cross Recessed Round Head Screw Bolt JL-SCR-100