... Stainless steel, Aluminum alloy,Surface Treatment: Chrome plating, Silver plating, Zinc plating, Nickel plating, Tin-plating, Passivate, Oxidation, Phosphorization, Radiant Plated,Process ... 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 ...