Stainless Steel Serrated Washers

Serrated washers are also commonly referred to as tooth washers due to the jagged tooth like serrations found on the surface of the inside or outside diameter of the washer. Another common term used to describe this style of washer is a shake proof washer. They could also be described by their DIN standards which are din6797j and din6797a for the internal and external toothed variations that we supply. Some people might simply call them tooth lock washers, due to the role that the serrations play in helping the washer to lock to the surface of its application.

The jagged tooth design of serrated washers acts as a locking mechanism that helps to make the washer resistant to loosening from vibrations, impact force or shaking. The serrations on the washer create friction as they drag against and bite into the surface that they are tightened into. They can be used to reduce the likelihood of a fastened bolt or nut from coming loose as a result of vibrations, shocks or movements within the application. Their ability to "shake proof" a fastened joint has earned them this moniker.

There are two main types of serrated washers, internal tooth lock washers and external tooth lock washers. Internal tooth lock washers have serrated teeth on the inside hole of the washer, also known as its inner diameter. The external tooth lock washers have the serrations on the outside edge of the washer. Both types of serrated washers are designed to prevent the loosening of fasteners caused by vibrations, movement and other forces. Determining whether an internally or externally toothed washer is better for an application will depend on the type of fastener being used and the available space within the fastened joint. Internal tooth lock washers are often used with screws, while external tooth lock washers are commonly used with bolts.

Tooth washers are commonly used in the energy industry within power generation plants to secure heavy duty turbines and generators that are subjected to constant movement and vibration during operation. Serrated washers also have a use case in electronics, where they can be used to secure the fastening of components such as control panels, circuit breakers and junction boxes. Finally, the resistance to vibrations that tooth washers provide is generally very useful in the automotive industry. Serrated washers are often installed into car components such as engine mounts, suspension systems and brake assemblies. Tooth lock washers are essential in these applications for maintaining secure connections and preventing failure in parts that constantly vibrate and suffer micro-movements as a result of the combustion engine of a car.

The jagged teeth on the outside or inside edge of serrated washers point towards a certain direction. This is because they are designed to bite into a particular surface during their application. For this reason, it is important to install tooth washers the right way around so that they can function as designed. Internal tooth lock washers were designed to bite into the underside of a fastener such as a screw head, bolt head or nut. This is because their primary task is to secure the fastener against vibrations and other forces that could cause it to loosen. So when installing an internally toothed washer you should always make sure that the serrated teeth point towards the fastening object that you want to secure, be it a screw head, bolt head or nut. External tooth lock washers work differently and have instead been designed to bite into the surface of the application that you are fastening. This means that when you install them, you should place the side with the teeth pointing up against the surface that you are bolting or screwing into. The teeth on externally serrated washers should not face towards the bolt head, screw head or nut. We know it can be confusing to know the correct use for washers in an application, so our team are happy to answer any questions. Feel free to use our contact us page for advice or help with installation.

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