Zinc Plating Process


Corrosion Resistance


Zinc plating process is usually deposited onto ferrous substrates to provide effective, powerful and beautiful corrosion resistance coating that improve the appearance of finished products.

Zinc Plating Process

This technique plays key roles on automotive industry. Depending on its processes, zinc plating is typically plated on parts such as brake calipers and fasteners, while zinc alloys plating, including zinc nickel and zinc iron process, are applied on stamp parts, drive shafts, and steering components.

At Okuno-Auromex, our extensive technical expertise provides our clients in selecting the most innovative coating solutions to meet their exceptionally high quality parts.

We supply a wide range of chemicals for zinc plating process including cost-effective cleaners, high performance brighteners for conventional zinc plating and zinc alloys plating, multi-shade passivations and excellent top coats.

Furthermore, Okuno-Auromex “green initiatives” delivers environmental friendly products such as boric free brighteners, silica and hexavalent free passivations. This meet the global environmental regulations such as REACH, RoHS and ELV compliant products.

Conventional Zinc Plating Process

Okuno-Auromex’s conventional zinc plating process includes both acid and alkaline plating. They can be applied on metal substrates as iron, steel or brass to provide superior attractive appearance and enhance outstanding properties. Our products are designed to meet the global quality and environmental standard and fulfill many industries, especially for automotive OEM’s manufacturer.


The rigorous regulation and a “ban” on cadmium plating have driven manufacturers of components to develop zinc alloys for suitable alternate plated deposits. Zinc alloys plating are deposited on ferrous substrates to improve their properties and enhance surface’s appearance. Metal alloys, such as nickel and ferrous, in solution provide superior physical properties than conventional zinc plating.

Okuno-Auromex provides a full package of zinc nickel plating and zinc iron plating. Our zinc nickel plating process includes alkaline plating solutions, while alkaline zinc iron plating process is delivered for specific parts plating.


By applying of only zinc plating, zinc is oxidized and corroded easily. So to improve corrosion protection effect and appearance, generally, chromating or passivation is applied. The passivated film is formed on zinc deposited surface.
The key component of passivation is chromium compound. However, hexavalent chromium which is contained in chromate film is prohibited due to harm for life and environment. So trivalent passivation has been applying in place of hexavalent passivation.

To support salt spray requirement and other worldwide standards such as WEEE, RoHS and ELV, Okuno-Auromex provides a full range of trivalent passivation covering from blue to iridescent and black shade. They are specific for acid and alkaline plating, zinc nickel plating and zinc iron plating. Our products are guaranteed in excellent corrosion resistance with attractive appearance. Recently, we offer cobalt-free passivation and anti-NOx generated passivation to support the green technology.


Only passivation is not enough to protect zinc layer with a long time. To define the plating standard, salt spray test method was created and post treatment technology was also developed to challenge this standard.
Main post treatment for zinc plating is top coat. The beginning top coat is invented for black passivation which is lower corrosion resistance than others and is easy to be scratched. Now many industries need maximum parts’ life. So top coats for blue and iridescent passivation are developed.

Okuno-Auromex’s top coat products improve the highest quality and enhance properties to meet automotive OEM’s requirement. We provide high performance products both organic and inorganic top coats including top coats for zinc on steel, zinc nickel and zinc iron process. Our top coats cover from blue to iridescent passivation and black passivation.