... , Washers/Gaskets, Check rings, Pins, Rivets and etc. 2. by head types Flat, Oval, Binding, Pan, Round, Truss, Button, PF, Pan washer ... , Cheese, Countersunk, Fillister, hexagon, Hexagon washer head, Hexagon socket button head and etc. 3. by type of drive inserts Phillilps ...