Zinc For Galvanizing

Four grades of zinc ingots (99.99 percent, 99.95 percent, 99.5 percent and 98.5 percent are generally used. B.S. 1005 lays down methods of sampling and analysis. Only silicon and phosphorus, of the usual steel impurities, have a noticeable effect on the quality of the zinc coating. It has been said that a medium silicon content of about 0.2 percent gives the best appearance and adhe­sion in galvanizing. In the steel wire industry, if the wire is not to be redrawn after galvanizing, addi­tions of cadmium and aluminum are beneficial, but when redrawing is necessary, aluminum alone should be used.