Washer, machine component that is used in conjunction with a screw fastener such as a bolt and nut and that usually serves either to keep the screw from loosening or to distribute the load from the nut or bolt head over a larger area. ... To prevent loosening, several other types of washers are used.

What happens if you dont use a washer?

Most notably, washers protect the surface from damage during installation. They distribute the pressure and prevent the fastener from moving or corroding. Skipping on washers can dramatically reduce the lifespan of how your product is put together. Ultimately, that leads to disaster for the product itself.

When should you use a flat washer?

Flat washers are used to protect surfaces by evenly distributing torque when a bolt or screw is tightened. A washer is a thin plate with a concentric hole that's typically used to evenly distribute the load of a threaded fastener.