Sherardizing is a surface coating process which gives superb long term corrosion protection to iron and steel products. The coating is uniform and closely follows the contours of the component. When the coated surface is zinc phosphated, it leaves a clean surface to which a further coating, such as paint, can readily be applied.

BS 4921:1988 "Specification for sherardized coatings on iron or steel" and BS 7371 -8:1998 "Coatings on metal fasteners. Specification for sherardized coatings" sets out the specifications for the coating thickness.