BS 4921:1973

Specifies coatings consisting principally of zinc applied to iron and steel articles by the sherardizing process to protect them against corrosion. Deals with the purity of the zinc powder used in the sherardizing process and with the thickness, appearance and adhesion of the coating. Two classes of coating thickness are specified together with the reference method of determining the coating thickness. Gives advice on the condition of the basis metal and the need for post treatments.