Zinc-nickel plating

Zinc-nickel plating electrodeposits a zinc alloy with 12–16% nickel, typically 0.0003–0.0005 in (8–12 µm) thick, topped with a trivalent passivate. It protects steel sacrificially like zinc but corrodes far more slowly, commonly 720–1,000 h to red rust in ASTM B117, and holds up after heat exposure. It is an automotive standard for brake, fuel and fastener parts and a cadmium replacement.

Add it to a part

Applies to: Carbon and alloy steels, including fasteners, stampings, brackets and hydraulic fittings
Adds: 5 days
Cost: Moderate

Colors

Clear / silver
Black

Specs

Zinc-nickel plating specifications
Alloy content	12–16% nickel, balance zinc
Thickness	0.0003–0.0005 in (8–12 µm) typical
Salt spray	Commonly 720–1,000 h to red rust in ASTM B117
Heat resistance	Keeps corrosion performance after heat exposure better than zinc
Passivate	Clear or black trivalent; sealer or topcoat optional
Hydrogen embrittlement	Relief bake hardened parts per ASTM B850

Call out on the drawing

ASTM B841 (zinc-nickel alloy deposits)
AMS 2417 (aerospace, cadmium replacement)
ISO 19598 (zinc and zinc alloy coatings, Cr(VI)-free)
Automotive OEM finish specs as called on the drawing

Materials it suits

Common on

Questions

Why use zinc-nickel instead of zinc?

Corrosion life is several times longer at the same thickness, the coating tolerates under-hood temperatures, and it causes less galvanic corrosion against aluminum. The premium pays off on automotive, outdoor and fastener parts.

Is zinc-nickel a replacement for cadmium plating?

Yes, in many aerospace and defense applications under AMS 2417, using low-embrittlement processes. Qualify it against the original cadmium requirements for lubricity and torque-tension on fasteners.

Is black zinc-nickel durable?

Black trivalent passivate on zinc-nickel with a sealer is one of the most durable black plated finishes and is common on automotive fasteners and brackets. It far outperforms black zinc in salt spray.