A washer is a common type of hardware that’s typially used to evenly distribute the force/load of a screw or nut. However, washers can also be used as spacers, wear pads, preload indicating devices, locking devices, prevent corrosion, and to minimize vibrations produced by a machine or equipment. While most people are familiar with the general concept of washers, you might be surprised to learn just how many different types are available. Today we’re going to break down some of the most common types of washers and how they work.
Plain Washers
The most common type of washers is plain washers, also known as flat washers. They are typically designed to spread the loan and protect the respective surface from damage. Plain washers can also be used when the hole is bigger than the nut. Common examples of plain washers include fender washers, spherical washers, wall washers and torque washers.
Spring Washers
A second type of washer is a spring washer. Spring washers are characterized by their axial flexibility. They are typically used in machines and equipment that create strong vibrations. Because of their axial flexibility, spring washers won’t loosen or come undone from the vibrations, making them ideal for such applications. Common examples of spring washers include belleville washers, curved disc washers, wave washers, split washers, tab washer and toothed locked washers.
Locking Washers
A locking washer is a special type of washer that’s used to prevent fastening or loosening, similar to the way in which a spring washer works. In fact, locking washers are essentially a sub-type of spring washers.
Type A and Type B Washers
You may notice that some washers are labeled as “Type A” and “Type B.” Creating by the American National Standards Institute (ANSI), Type A refers to steel washers with a broad tolerance, whereas Type B refers to flat washers with a tighter tolerance. Type B washers also feature outside diameters that are narrow, regular or wide.
Material Types
Of course, different washers are made of different materials. Steel is the most common type of material used in the construction of washers. Steel washers include carbon steel, spring steel and stainless steel. Other metals in which washers are available include copper, brass, aluminum, titanium, bronze, zinc and iron.
In addition to metal, materials such as alloy, plastic and nylon are also used to produce washers.