They are designed to prevent a nut or bolt head from loosening with the strut action of the teeth. They work exceptional way with larger screw or bolt heads. The purpose of installing washers in a typical bolting system is to distribute the loads under bolt heads and nuts by providing a larger area under stress.

A Internal Star Washer is a thin plate (usually disk-shaped) with pointed edges in the internal section with a hole (usually in the middle) that is normally used to distribute the load of a threaded fastener, such as a bolt or nut. Other uses are as a spacer, spring washer, wear pad, preload indicating device, locking device, and to reduce vibration (rubber washer). Washers often have an outer diameter (OD) about twice their inner diameter (ID), but this can vary quite widely. Washers are usually made of metal or plastic depending on the use

• Plain Finish Internal Star Washer: Internal Star Washer with No Coating.
• Zinc and Yellow Chromate Internal Star Washer: Offers better resistant to corrosion to Internal Star Washer than Chromatic.
• Zinc and Chromate Internal Star Washer: Silvery and offers resistant to corrosion for Internal Star Washer.
• Zinc Plated Internal Star Washer: Internal Star Washer Coated with Zinc.
• Hot Dipped Galvanized(HDG) Internal Star Washer: Offers superior resistant to corrosion due to the dipping of Internal Star Washer in the molten zinc.