name: screws material: stainless steel, copper, brass, alluminum alloy, etc ... Studs, Nuts, Tapping screws, Wooden screws, Washers/Gaskets, Check rings, Pins, Rivets and etc. 2. by head types Flat, Oval, Binding, ... are bolts, screws, nuts, machine screws, plain washers, spring lock washers, wood screws, tapping screws, drilling screws, chipboard screws, drywall screws, furniture screws, rivets, anchors ...