Understanding Washers and Shims


Understanding Washers and Shims

Here at Phoenix Specialty Manufacturing, there are some questions that we hear more often than others. One particular topic that people often are confused about is the difference between washers and shims. They can seem very similar, but it is important that you understand these tools if you plan on using them. Each one serves a different purpose, so in some situations one will be preferred over the other in order to get the results you want.


A washer is often made of metal, but can be plastic as well. It is typically doughnut-shaped, and the diameter around the outside is usually twice the size of the diameter of the inside. It is most often used to distribute the load of a screw or a nut, so the fastener will not break when it has to bear weight. It can also be used as a spacer, a preload indicating device, or a wear pad. People will find other uses for washers as well, but these are the most common.

There are three main types of washers: plain, spring, and locking. Plain washers are used to distribute a weight load, can serve as insulation, and will prevent damage to the surface that the fastener holds to. Spring washers are more flexible, and they will help reduce vibration. Locking washers will hold a fastener in place so it does not loosen or back out over time.


A shim is made of many different materials, such as wood, metal, plastic, or stone. It can be any shape that it needs to be in order to serve its purpose, which is to support something or fill in a space. It can be used in a car to adjust the space between two parts, or it can be as simple as something that goes underneath the leg of a table to stabilize it. By filling in a space, a shim can reduce the wear of both objects and keep them protected. A shim is often very thin, but its thickness will be chosen based on the size of the gap that needs to be filled.

The Main Difference

As you learn about each tool, you may still be confused about what the difference between these two items is. In some cases, they are used for very similar purposes and may even be interchangeable. However, a shim is mostly used as a spacer, while a washer is most often used to distribute a load for any type of threaded fastener.

When working on your next project, you may need to use one of these tools. Choosing the right tool will help you ensure that you get the results you want. If you are at all confused about which would be better for your use, you can talk to someone at Phoenix Specialty Manufacturing. Our professionals should be able to help you determine which tool is the right one to use, and can even direct you to the right size and shape of washer or shim.

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