Fastener Coatings

A fastener’s job is to connect and secure objects to one another. It is essential that applications use the appropriate fastener for structural integrity. This includes taking into consideration a fastener’s coating. Coatings provide protection to the metal underneath. Since exposure to harsh environments or chemicals can drastically shorten a fastener’s life span, it is important to coat exposed fasteners properly.

Salt Spray Testing

Manufacturers like Fastco rely on salt spray testing to determine the corrosion resistance of coatings. The more hours of salt spray that the coating can withstand before oxidation or rust occurs, the better (and often more expensive) the coating.

Zinc Coating and Others

One of the most popular fastener coatings available is zinc. In fact, zinc coatings are so popular that they represent nearly 60% of total annual zinc consumption. It is a relatively inexpensive coating and protects well against rust, making zinc-coated fasteners perfect for humid environments.

Beyond standard zinc coatings, a zinc-nickel coating adds longevity if a part exists in a corrosive environment. Zinc-phosphate coating is a lower performance coating used as a primer or when little corrosion protection is needed.

Electroplating and Galvanizing

Zinc is often applied via electroplating, a process that uses an electric current to dissolve metal and adhere it to a surface. Besides zinc & nickel, tin, gold, silver, and copper can all be used in electroplating.

Electroplated coatings are thin, much thinner than galvanized coatings, which are more durable and provide longer protection against rust and corrosion than electroplating. While more durable, galvanized plating may not be as aesthetically pleasing as electroplating.

This article is only brushing the surface of available coatings and coating methods for fasteners. If you’re looking for a specific coating, Fastco works with a number of trusted outside processors to meet your fastener coating needs.