Hex Cap Screws are bolts with e hexgonal head. Hex cap Sccrews offer a tighter tolerance than its fully threaded tap bolt counterpart and are the most commonly used bolt in the consctruction, automotive, and food industries. A Galvanized coating is the process of applying a protective layer of zinc that prevents rusting. These bolts are coated by the hot dip galvanizing process, in which they are dipped into a bath of molten zinc. These fasteners are a great choice for use with pressure treated wood or any application that is exposed to elements that may cause corrosion.