How Are Washers Made

Washer Materials

Washers should be softer than the material of the machine part they’re installed on. Washers are made from mild steel, copper, brass, aluminum, lead, and cardboard. They’re used to protect part surfaces and to distribute the clamping force of a nut and bolt head over a wider surface (especially on soft metal, wood, and PVC materials).

Standard Washer Production

Washers are generally mass-produced from sheet metal using the punch-press method.

Material Selection

In washer production, materials such as steel, stainless steel, or brass are chosen depending on the intended use environment.

Difference of Spring Washers

Unlike flat washers, spring washers provide flexibility that helps prevent the connection from loosening.

How Are Washers Made

Washers are generally mass-produced by cutting strip sheet material on press machines using cutting dies. A washer should not deform during manufacture, its surfaces should be flat and smooth, and its surfaces should be free of defects such as burrs, cracks, or pitting.

In the figure, we see a washer cutting die in cross-section while operating

Typically, a cutting die designed and drafted into a technical drawing according to the appropriate dimensions is mounted securely and correctly onto hydraulic or manually operated (eccentric) presses. For each washer stamped, the operator needs to feed the strip forward and trigger the mechanism that lowers the press head.

Washer cutting dies are designed so that one washer is produced with each stroke of the press. These types of dies have two male punches. In addition, when needed, or to avoid material waste, large-diameter washers can also have a second, or even a third, washer produced from a single die.

In the figure, we see the steps in the washer-cutting process. Click here for the detailed video

The sharp edges of washers must be deburred. For this, the cutting points of the female die and male punches must be maximally smooth. Washers that require precision or where appearance matters, or those with a large thickness, can be produced on lathes.

Related Questions

A hard washer can scratch or deform the surface beneath it when the bolt is tightened. A softer washer transmits the clamping force by spreading it over a wide area without damaging the surface.

While a flat washer only spreads the load over a wide area, a spring washer, thanks to its flexibility, applies a continuous clamping force to the connection. This continuous pressure prevents the nut from gradually loosening under vibration.