ThePipingMart Blog Fasteners 5 Types of Star Lock Washers and Their Uses

5 Types of Star Lock Washers and Their Uses

Star Lock Washers

Lock washers prevent nuts and bolts from loosening due to vibrations or torque. They come in different shapes and sizes to accommodate different fastening needs. The star lock washer is one of the most popular types. It gets its name from the star-shaped teeth that bite into the surface of the bolt or nut to provide secure fastening. This article will discuss the different types of star lock washers and their applications.

Types of Star Lock Washers

Internal star lock Washers

Internal star lock washers are designed to fit inside the hex of a nut. They have internal star-shaped teeth that grip the nut’s flat surface to prevent it from loosening. These washers are typically made from hardened steel to resist wear and tear and are commonly used in automotive and other heavy-duty applications. Because internal star lock washers are installed internally, they provide a smooth, clean appearance on the outside of the fastener.

External star lock Washers

External star lock washers are placed under the head or nut of a bolt, providing a smooth surface on the underside of the fastener. These washers have a star-shaped profile that embeds into the material’s surface when tightened, providing an extra grip that helps prevent the bolt or nut from loosening. External star lock washers are often used in precision equipment and electronics where a flat, discreet surface is essential.

Combination Star Lock Washers

Combination star lock washers feature internal and external teeth, providing extra grip and preventing loosening. They are typically used in automotive and other high-stress applications where heavy vibration or torque can cause traditional fasteners to loosen. Combination star lock washers come in various shapes and gauges, so selecting the suitable washer for the specific application is crucial.

Toothed Washers

Also known as wavy washers, toothed washers feature a wavy shape that provides additional grip to the bolt or nut. They can be installed beneath the head of the bolt or on the surface of the nut. Toothed washers also help reduce the chance of damage to the material’s surface due to the teeth’ extra grip. These washers are commonly used in electrical and electronic applications.

Crimped Washers

Crimped washers have a crimped shape with sharp edges for maximum gripping power. They can be installed under the head of the bolt or on the surface of the nut. Crimped washers are typically used in heavy-duty machinery, automotive applications, and construction industries.


Star lock washers are essential components that provide extra grip and prevent bolts and nuts from loosening under heavy vibration or torque by understanding the different types of star lock washers and their applications. Internal, external, combination, toothed, and crimped washers offer unique benefits and are crucial to proper fastening and long-lasting security. Be sure to choose the suitable lock washer for your application and follow reasonable installation procedures for the best results.

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