Corrosion Resistance of Washers

What You Should Know About Corrosion Resistance of Washers

You heard about washers but you do not actually know its applications. Washers are considered fasteners that have an important role in many industrial and construction applications. Picking the right standard washers in all sizes and materials is not easy because of the overwhelming types but you can make an informed decision based on the corrosion resistance.

Before tackling the corrosion resistance, you should first know the types of washers, which include plain washers, spring washers and locking washers. Plain washers have the ability to distribute the load equally to avoid the destruction of the surface being repaired. It can also serve as some sort of electric insulation. Spring washers, on the other hand, are utilised to prevent loosening against vibrations. Finally, locking washers secure the fasteners by preventing the loosening or tightening.

locking washers

According to the American National Standards Institute (ANSI) delivered standards for the universal use of flat washers. There’s Type A. Type A refers to the steel washers with wide tolerances. It is useful for washers where precision is not important. Type B refers to flat washers with firm tolerances. It is useful for washers where the outside diameters are wide, regular and narrow.

There is another standard formulated by The British Standard for Metric Series Metal Washers (BS4320). There are different forms of flat washers From A (flat washers with normal diameter but normal thickness), Form B (flat washers with normal diameter nit light thickness), Form C (flat washers with large diameter but normal thickness), Form D (flat washers with large diameter but light thickness), Form E (flat washers with larger diameter but normal thickness), Form F (flat washers with larger diameter but normal thickness) and Form G (flat washer with largest diameter and larger thickness).

Going back to the corrosion resistance, it means how well a material can endure destruction caused by chemical reactions and oxidation. Materials are in two forms – metallic and non-metallic. Metallic materials of washers include brass, aluminum, bronze, nickel, copper, steel, and titanium. Non-metallic materials include asbestos, felt, nylon, leather, polycarbonate, polyester, rubber, polypropylene and PVC. There are techniques that you can use to enhance the corrosion resistance properties of particular materials. Here’s an idea:

Metallic coatings

You already know the metallic materials of washers. In preventing corrosion for these materials, there is a coating like nickel, zinc, and cadmium. Nickel coatings give protection from corrosion when the finish is non-porous. The zinc coating acts as a sacrificial layer before the actual washer material is harmed. Cadmium coatings generate high-quality protection but it is toxic.


This is the coating of washers using metals like chromium and silver.


It provides strong protection but highly abrasive. The washer will be incorporated by zinc-phosphate with protective oil.


Exposing the washer material (specifically steel) to alkali salt solution will lead to oxidizing. This will then create a corrosion resistant surface with color.

Chemical plating

This will create a highly corrosion resistant surface. It uses nickel phosphor that is precipitated unto the washer surface creating high-quality corrosion-resistance.