Internal star washers provide a secure locking mechanism by gripping the surface they are installed on, preventing loosening due to vibrations. They are commonly used in electrical and mechanical assemblies to maintain tight connections.

Internal star washers have teeth facing inward, ideal for smaller components or when aesthetics are a concern. External star washers have outward-facing teeth, offering greater holding power on larger surfaces.

Internal star washers are typically made from steel, stainless steel, or brass. Steel washers are often zinc-plated for corrosion resistance, while stainless steel is preferred for high-durability applications.

While some internal star washers can be reused, their effectiveness may decrease after removal due to deformation of the teeth. It's generally recommended to replace them to ensure optimal performance.