Complete Guide to Washers: Types, Material, and Size Chart

Manufacturers use types of washers for making and coupling parts. Below are different washers and their uses.

Plain Washers

Plain washers are the most popular kind. They disperse force and safeguard the item that the screw or nut is attached to. It also helps the screw or nut fit properly into a large hole. Plain washers in this category include:

Torque Washer

The principal uses for these washers are in the woodworking industry. When a nut is tightened, the outside prongs of the washers feature square holes that prevent the accompanying bolt from spinning.

Flat washer

Flat washers have a hole in the center and are flat or disc-shaped. They are ideal for small head screws because they spread the weight across a wider surface.

Fender washer

Fender washers are bigger and have a tiny hole in the center. They can spread out the load across a broader region. These washers are primarily used in sheet metal manufacturing, automotive fenders, and plumbing industries.

Finishing or countersunk washer

Countersunk washers in this category often create a flush finish upon securing with a flat-head countersunk screw. This ability to catch countersunk fasteners is due to its sunken top.

Shoulder washer

Shoulder washer fasteners in this category come in various materials, including PTFE, fiberglass, metal, phenolic, and nylon. These shoulder-like shaped washers often serve as insulators for screws and wires.

C-washer

A C-washer resembles a flat washer, but the primary difference is the hole cut from its center to form a C-shape. One primary advantage of this type of washer is that it is possible to adjust, remove or modify it without removing the fastener.

Spring Washers

For machinery that vibrates vigorously while operating, spring washers are ideal. They move with vibrations, thus preventing them from being loose or unfastened because of their axial flexibility, consequently increasing the joint’s flexibility. There are different types of spring washers.

Belleville or Conical washer

These washers, often called conical spring washers, are employed to maintain tension during the assembly’s thermal expansion and contraction. They can support large weights while deflecting only slightly.

Dome spring washer

A dome washer is renowned for having a large load capacity with minimal deflection. They also absorb excessive vibrations and flatten the surface.

In addition, they have ground curves that create a load-bearing surface that is flatter. It can be used everywhere. A crescent spring washer would be useful, although flattening the surface is also necessary.

Wave spring washer

Wave spring washers are curved in two directions and are typically employed as cushions or spacers. They can support a moderate amount of weight and guard against excessive wear on the surface.

Finger spring washer

Made using carbon steel, finger spring steel washers comprise three curved flanges. They help lessen vibration, skidding wear, additional wear, dampening, and noise on rotating parts.

Carbon steel is commonly used to make finger spring washers. They blend the wave washer’s predetermined load spots with the casing washer’s flexibility.

Crescent spring washer

The crescent spring washer, also called curved spring washer, has a somewhat curved appearance that gives them a lighter pressure while maintaining flexibility. They have an extensive deflection range and can withstand extremely light loads.

These washers have linear load-deflection characteristics and offer uniform spring rates throughout the deflection range.

Lock Washers

Lock washers are designed to help prevent the screws and nuts from rotating toward their loosening position. Consequently, this preserves them even during intense vibrations produced by the machine or equipment’s operation. In other words, they hold the fasteners that tend to loosen due to friction in place. The different types of lock washers include:

Split lock washer

The split lock washer, commonly called a helical washer, is used to secure fasteners. They are non-continuous rings bent inward and outward in opposing directions. When this fastener is used to secure the bent, both ends of the bent flatten out and dig into the mating surface.

External tooth lock washer

External tooth lock washers employ a teeth-structural action to keep the nut or screw head from coming undone. They function better with screws that have a larger head. The numerous teeth on their outer diameter bite into the surface to produce exceptional compression resistance, consequently ensuring they provide the highest level of torsional resistance.

Internal tooth lock washer

On the inside diameter of the internal tooth locker are many teeth that prevent the bolt or nut head from loosening. They serve to dampen noise and shock while locking shallow-head fasteners into position.

Specialized Washers

Specialized washers do not fall expressly into any of the above categories. Here is their information.

Keps nut

Also referred to as K-lock nuts, these washers with built-in washers facilitate spinning. The assembly functions more efficiently, thanks to the nuts.

Top hat washers

These washers are perfect to utilize while repairing or installing a tap because they are typically used in plumbing applications.

Keyed washers

Typically used between bolts to prevent them from spinning, these washers are placed keyed washers typically find application in the automotive industry. These washers have an internal tab that prevents the automobile shaft from rotating. They also find use in chassis parts and cylinder heads.

Insulating shoulder washer

Insulating shoulder washers are often made from nylon, peek, plastic, and other insulating materials. The best use for these washers is in the electrical sector, where they help isolate mounting screws from electrical current.

Gaskets

Gaskets, also known as O-rings, and made of rubber, come in different shapes and sizes depending on the purpose. It is a mechanical seal that fills the space between two or more surfaces in contact to prevent leaks and spills. In the automotive sector, their primary use is to slam shut oil and gas connectors and stop leaks.

Aside from rubber, gaskets can be made from light metals, such as aluminum, and other metals. These washers maintain a tight seal regardless of pressure and temperature, preventing gases and liquids from escaping.