Washers

A washer is a thin plate with a hole (typically a disk-shaped one, but sometimes a square one) normal for distributing the load of a threaded fixing device such as a nut and bolt. Other uses include the spacer, spring, wear pad and preload indicating device, locker (Belleville washer, wave washer), and to for reduction of vibration (rubber washer). Washers are often had twice the inner diameter (ID) as compared to the outside diameter (OD), but this can vary considerably.Washers can be made of metal or plastic. High quality bolted joints require hardened steel washers to avoid pre-charge loss due to brinelling after applying the torque. Washers are also important to prevent galvanic corrosion, especially by isolating aluminum surface steel screws. It can also be used as a bearing in rotating applications. A thrust washer is used when neither cost-effectiveness nor spatial constraints are required to support the rolling element. The coating is either to enhance their surface or to offer a strong lubricant (i.e. a self-lubricating surface) to reduce wear and friction.

Types of washer available At Vision Alloys

Uses of Washers with Fasteners

Load Distribution

The main aim of the most washer is that the load of the threaded fixing with which they are used is distributed evenly. Threaded bolts stress the material they are driven into. For example, a screw can cause the wood to crack the surface. Washers reduce the risk of such damage by uniformly distributing the load of the attachment across the material surface. The use of washers is not necessary for all materials. But washers are useful to protect against stress-related damages from wood and other relatively soft materials when the threaded bolt is pushed into the material.

Spacing

Washers can be used as spacer as well. Why would you even need a spacer for a threaded bolt to an object? If the threaded fastener is longer than the object’s depth, you can’t push it into the subject — at least without some fastener sticking to the back of the object. Drive a 4-inch screw into a 3 “deep object, leading 1 inch of the tip of the screw out of the object backward. The use of washers is a simple solution. Before driving into the object, placing washers in the threaded screw creates padding to avoid a too deep fixation.

Vibration Absorption

Some washers are designed for vibration absorption. They are not usually made of metal, known as vibration damping or washing reducing vibrations. They are made of plastic, rubber or urethane. Weaker materials such as these can absorb vibrations more efficiently than hard, including metal materials. If a threaded fastener is used for connecting two objects, one of which vibrates aggressively, the other object can be protected from damage through vibration-reducing washers.

Liquid Protection

Other washer types prevent water and liquids from entering. Often used to create a waterproof seal in water pipes and connections. Like damping vibration washers, washers for liquid damping are made of a soft material which completely presses the object’s surface.

Reference:

https://en.wikipedia.org/wiki/Washer_(hardware)

https://monroeengineering.com/blog/the-purpose-of-washers-and-why-theyre-used-with-fasteners/