Commercial zinc plating has a standard minimum thickness of 0.00015 inches. A clear or bluish chromate finish is applied on top of the zinc.
Yellow chromate offers a greater degree of protection from white corrosion than does clear chromate.
However, cadmium is a much more toxic metal than zinc, which makes the plating process more difficult and costly. The standard most commercial platers use when applying cadmium is a minimum thickness of .0002 inches. A supplemental wax coating is often added as a lubricant when cadmium is used on prevailing torque lock nuts. Hot-Dip Galvanized Hot dip galvanizing is generally the most effective way to apply a sufficient thickness of zinc to threaded fasteners for the zinc to serve as a corrosion protectant in harsh environments. Nickel Nickel has more of a silver color to it than zinc and has similar corrosion resistant characteristics.