Zinc Plating vs. Zinc Flake Coating: What’s the Difference?

Applying zinc finishing to small metal components, such as fasteners, screws, and switch plates, enhances the components’ corrosion resistance. Zinc is a bluish-white metal commonly applied to iron, brass, and other alloys via one of two methods—zinc plating or zinc flake coating—each of which carries its unique advantages and use cases.

This blog post provides an overview of the two methods, outlining their basic processes, benefits, and typical applications.

Zinc Plating: Overview

Zinc plating—also referred to as galvanization—employs an electrical current to facilitate the application of a thin coat of zinc to the surface of a metal component. The zinc oxidizes, creating a protective layer of zinc oxide that prevents the base metal from being exposed to the surrounding environment. It is largely used for iron or steel parts that would otherwise rust when exposed to air or water.

Benefits of Zinc Plating

In addition to corrosion resistance, steel and iron plated with zinc demonstrate several advantages over their non-plated counterparts, such as:

• Higher strength
• Easier formability
• Lighter material weight
• Greater recyclability
• Superior cost-effectiveness

Applications of Zinc Plating

Zinc-plated components find application throughout industries in indoor and mildly corrosive environments. Typical parts that undergo the zinc plating process include:

• Automotive industry: steering transmission parts and brake callipers
• Hardware industry: brackets and fasteners
• Military industry: Underbody and suspension components, weapon systems, arms and accessories

Industry professionals may add a chromate-conversion coating for components subjected to more corrosive environments for greater corrosion resistance.

Zinc Flake Coating: Overview

During the design of everything from mechanical assemblies to buildings, corrosion protection is a key consideration. Even the smallest components, such as nuts and bolts, must be protected from corrosion. Otherwise, they risk compromising the integrity of the entire system or structure. Zinc flake coating is an ideal solution for these applications. These coatings typically contain a mix of zinc and aluminium flakes. They are applied in two layers—a base coat and a top coat—the characteristics of which combine to satisfy the requirements of the application. When a zinc flake coated part is exposed to a corrosive compound, the zinc sacrifices itself to protect the base metal.

Zinc Flake Coating Benefits

Beyond protecting iron, steel, and other metals from corrosion due to atmospheric compounds, salt spray, and mild chemicals, zinc flake coatings offer many other benefits, such as:

• Fewer corrosion byproducts, or white rust, than other types of zinc protection
• Broader versatility for parts of different shapes, sizes, and geometries with options for varying layer thicknesses and colours
• Better protection against hydrogen embrittlement
• Some electrical conductivity
• Greater wear and extreme temperature resistance

Applications for Zinc Flake Coating

Zinc flake coatings are applied to a variety of parts and system components used in a diverse set of industrial applications, including:

• Automotive industry: Automotive sub-frames, chassis assemblies, fasteners, springs
• MEP industry: Construction building components
• Commercial/recreational applications: Home appliances
• Industrial/manufacturing applications: Threaded fasteners, small integrated components such as bolts, nuts, pressings, springs, and clips
• Utilities and energy industry: Wind energy generators

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