These forgefix twist nails are a unique twisted shank nail for attaching metalwork joists hangers straps etc the twisted shank assists in absorbing movement that may occur in construction they have a sheradised finish for corrosion resistance this finish is a thermal diffusion process in which zinc powder is vaporised and diffuses to the surface of the twist nail to form a sacrificial corrosion protective zinc iron alloy coating thus dramatically increasing the nails durability applicationthe tw