What are retaining washers?

Retaining washers are also known by other names which hint at their purpose: anti-loss washers and retention washers. These are used to keep assemblies in place, typically in industrial and automotive applications.

In this guide, we'll cover:

• The purpose of retaining washers
• Types of retaining washers
• What are sealing washers?
• Plastic retaining washers

More common are retaining washers that have a round hole with internal protrusions. Still others have one round hole with no protrusions, or teeth. Retaining washer types are designed to:

• Retain screws on an outer panel
• Prevent screws from falling when unfastened

When the washer is placed over the screw, the internal lugs within the washer grip the male thread. This is especially helpful in the automotive industry, where screws are used upright. For speed of assembly, it’s critical to use a washer that stays in place as the screw is installed.

Many retaining washers are excellent for pre-assembly. This in turn reduces your end assembly cost while saving time. These washers are also used as a temporary mount for fasteners. They’re often thin to minimise the gap they create on a flat panel. The secure hold that retaining washers provide make it ideal for applications when vibration is present.

This also makes them a type of shaft retaining washer. They act as shoulders to retain a specific component or assembly. In the example here, the lip makes assembly and disassembly easy. Other types of clips require a retaining washer tool for installation and retaining washer removal.

You can learn more about washers and other fasteners in our Ultimate guide to fasteners.

Types of retaining washers

Below are push-on retainer washers that slide over the screw shank. These retaining lock washers are ideal for pre-assembly.

What are sealing washers?

You might also need sealing washers, which are designed to create a close-fitting, water-tight seal. They’re often used in plumbing applications or to maintain an ingress-protection rating between cable glands and equipment.

Plastic retaining washers

Metal retaining washers are available, with the most common ones being aluminium and stainless-steel retaining washers. But plastic is becoming the popular choice for multiple reasons:

• Insulation against moisture and electricity
• Ease of assembly
• Absorbs vibration
• Weather resistance
• Cost

Plastics are also lightweight, which makes it especially popular with an automotive industry tasked with lowering emissions. They’re also ideal for electric vehicles, which also needs lightweight solutions. Nylon retaining washers are the most common, but other plastics are good choices too, depending on your application. You can compare their characteristics below to determine the best one for you.

Download free CADs and try before you buy

Free CADs are available for most solutions, which you can download. You can also request free samples to make sure you’ve chosen exactly what you need. If you’re not quite sure which screw retaining washer will work best for your application, our experts are always happy to advise you.

Whatever your requirements, you can depend on fast despatch. Request your free samples or download free CADs now.

Questions?

Email us at sales@essentracomponents.co.uk or speak to one of our experts for further information on the ideal solution for your application 0345 528 0474.