ThePipingMart Blog Fasteners Flat Washers vs Plain Washers – What’s the Difference

Flat Washers vs Plain Washers – What’s the Difference

Flat Washers vs Plain Washers

Regarding plumbing fixtures, washers play a significant role in protecting joints from leaks. However, two types of washers are commonly used in plumbing- flat and plain. It can be challenging to choose between the two, especially if you need to familiarize yourself with the differences. In this blog post, we’ll explain the differences between flat and plain washers and help you decide which is best for your needs.

What is Flat Washers?

Flat washers, as the name suggests, have a flat surface with rounded edges or sharp edges. These washers are used on bolts and screws to distribute the load evenly and prevent damage to the material. Flat washers are also used to protect the material’s surface from damage due to the tightening of the bolt. They are usually made of steel, brass, or nylon and come in various sizes.

What is Plain Washers?

Plain washers, on the other hand, have a curved surface on both sides, and the edges are flat. They are used to prevent leaks on tapped holes and with bolts and screws. Plain washers are typically made of soft materials such as brass or copper to ensure a tight seal. They come in standard sizes and are commonly used in plumbing fixtures.

Differences Between Flat Washers and Plain Washers

The main difference between flat washers and plain washers is their purpose. Flat washers distribute the load evenly and prevent damage to the material, while plain washers provide a tight seal and prevent leaks. The shape of the washers also differs, with flat washers having a flat surface and rounded or sharp edges and plain washers having a curved surface on both sides and flat edges.

Which One Should You Choose?

The choice between flat washers and plain washers depends on the purpose you’re using them for. Flat washers are the way to go if you’re looking to distribute the load evenly, prevent damage to the material, or protect the surface from damage. On the other hand, plain washers are the right choice if you’re looking to prevent leaks or provide a tight seal. Choosing the right size and material for the washer is important to ensure proper fitting and functionality.


Flat and plain washers may seem similar, but their purpose and shape set them apart. When choosing between the two, consider the purpose you want to achieve and the material you’re working with to make an informed decision. Both washers are affordable and readily available in hardware stores, so take the time to choose the right one for your plumbing fixture. Properly fitted and installed washers will ensure leak-free plumbing fixtures and a longer lifespan for your equipment.

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