Washer (hardware)

A washer is a thin plate with a hole.

It is usually made of metal or plastic.

We use it with a bolt or a nut. It helps spread the weight of the bolt. This stops the surface from getting damaged.

Some washers act like a spring. They help keep parts tight if things shake.

Other washers have teeth on them. These teeth bite into a surface. This stops the bolt from turning too much.

Washers are very helpful for building things.

A washer is a thin plate with a hole in the middle.

Most washers are made of metal or plastic. They are often used with a bolt or a nut.

One common type is the plain washer.

These help spread the load of a fastener. This prevents damage to the surface being fixed. Some plain washers are very large. These are called fender washers. They help spread weight on thin sheet metal.

Other washers act like a spring.

This helps keep parts tight if they shake. A split washer is a ring split at one point. It creates a spring force to stop things from loosening.

Some washers have teeth.

These teeth bite into the surface. This helps stop the bolt from turning. There are star washers with teeth on the edges. These work well on soft materials like plastic.

Washers can also be used as gaskets. These help seal against water or gas leaks. They are often used in pipes and taps.

A washer is a thin plate used in building and repair.

Most washers are shaped like a disk with a hole in the middle. They are often used with a threaded fastener like a bolt or a nut. The main job of a washer is to spread the load. This means it takes the pressure from the bolt and spreads it over a wider area. This helps protect the surface from getting damaged.

Some washers are also used as spacers or to stop parts from rubbing together.

There are different ways these tools work. A plain washer spreads weight to keep things steady. A spring washer, like a split washer, has a bit of flexibility. It acts like a tiny spring to keep the bolt tight even if there is shaking.

Some washers have teeth or serrations on their edges. These teeth bite into the surface to stop the bolt from spinning. Other types, called gaskets, are used to create a seal. They can stop water or gas from leaking out of a pipe or a tap.

People have used these tools for a very long time. The word "washer" was first recorded in the year 1346. However, the specific definition we use today was not recorded until 1611. Even though we do not know exactly where the word came from, it has been around for centuries. Over time, people have made many special shapes to solve different problems. This history shows how important small parts are to big machines.

There are many specific kinds of washers used in science and industry. A fender washer has a very large outer diameter to spread weight on thin metal.

An anchor plate is a huge washer used to strengthen the walls of masonry buildings.

In Germany, people sometimes use wave washers to help lock parts in place.

Some washers are made of very strong materials like hardened steel. Others are made of plastic, rubber, or even copper to stop electricity or leaks.

You can find washers in almost everything you use. They are inside the taps in your kitchen to stop leaks. They are in the cars you ride in to keep parts from shaking loose.

Even the bolts holding a bicycle together might use a keyed washer to stay in place. Whether they are made of metal or plastic, these small plates make sure our world stays held together safely.

A washer is a thin plate used in mechanical engineering and construction.

Most washers are disk-shaped with a central hole. They are typically placed between a threaded fastener, like a bolt or nut, and the surface being fastened. The primary purpose of a washer is to distribute the load of the fastener. This prevents the fastener from crushing or damaging the material underneath.

Beyond load distribution, washers serve as spacers, bearings, or locking devices. They can also act as insulators to prevent electrical flow or galvanic corrosion. This corrosion happens when different metals, like steel and aluminum, touch each other.

Plain washers, often called flat washers, are the most common type. They provide a smooth surface to spread pressure evenly.

Some versions, known as fender washers, have a very large outer diameter. These are useful for spreading loads on thin sheet metal, such as automobile fenders. In the United Kingdom, these are often called penny washers. Another specialized version is the torque washer. These have a square hole to fit a carriage bolt. The teeth on these washers bite into wood to prevent the bolt from spinning while tightening.

Spring washers use axial flexibility to maintain tension in a joint. A common type is the split washer, which is a ring split at one point. It is bent into a helical shape to create spring force. This force creates friction between the bolt and the nut. This friction helps prevent the fastener from loosening due to vibration.

Other spring washers include the Belleville washer. This is a conical, or cup-shaped, washer that provides significant force when compressed.

Wave washers are similar but exert less force and have a wavy shape.

Locking washers use physical interference to stop rotation. Toothed lock washers, or star washers, have serrations that bite into the surface.

These are very effective on soft materials like plastic or aluminum. There are four main styles: internal, external, combination, and countersunk. Internal star washers have teeth on the inner edge for a better look. External star washers have teeth on the outer edge for more holding power.

Combination washers use both edges for maximum grip. These teeth can also provide a conductive path for electrical grounding by cutting through surface paint.

Advanced locking technology includes the wedge lock washer. This is a hardened, two-piece washer with radial teeth.

The two halves form a wedge seam. This design requires extra tension to separate the parts after they are tightened. This makes them excellent for preventing loosening caused by heavy vibration. Another type is the tab washer. This metal piece has a side tab that a user bends against a nut. This physically blocks the nut from turning around the shaft.

Washers are manufactured from a wide range of materials to suit specific needs. Steel is common, especially hardened steel for high-quality bolted joints. This prevents a phenomenon called brinelling, where the surface is dented under high torque. Non-ferrous metals like copper, brass, and titanium are also used.

For electrical insulation, engineers use plastics like nylon or PTFE, also known as Teflon. Phenolic washers are another choice for insulation because they are heat resistant and tough. In plumbing, soft metal washers like copper or aluminum are used as crush washers. These create a seal to prevent liquid or gas leaks in engines and pipes.

While they look similar, washers and gaskets serve different roles. A washer is usually a structural component for a fastener. A gasket is a seal used to prevent leaks in connections like taps or valves. Some people colloquially call these gaskets "washers," but they are designed differently. For example, a Dowty washer uses a central rubber ring to create a high-pressure seal. Understanding these distinctions is vital for maintaining machines and building structures safely.