Specifies requirements, including coating thickness, for electroplated coatings of zinc on threaded steel fasteners having inch series threads. It includes a method for the calculation of the degree of thread modification to accommodate thicker coatings when additional protection against corrosion is required. Appendices give details of surface areas for the various types of screws, bolts and nuts; recommended sampling procedures; examples of effect of manufacturing tolerances on plating thickness calculations; and heat treatment procedures.