Why is a chromate applied to zinc plated parts?
Untreated zinc will begin to oxidize rapidly. The resultant white powder (zinc oxide) is a sign of the zinc “sacrificing” itself to protect the metal it’s covering. A dichromate conversion coating provides an extra layer of protection by preventing the oxidation of the zinc plate. Chromated zinc lasts longer, looks better and provides the added benefit of increased galvanic compatibility with aluminum items, such as cylinder heads.
