scope:

The materials defined by these specifications are corrosion protective coatings applied sequentially per supplier specifications over steel. They consist of an alkaline zinc nickel alloy electrodeposit and a trivalent chromium passivate/adhesion promoter. A2, A3 and A4 are followed respectively by an organic seal, a cathodic electrocoat, or a waterborne top coat. When used with an integrally cured torque modified post dip, these processes provide consistent torque-tension control.

All processes are free of hexavalent chromium, lead and cadmium.