EXTERNAL TOOTH WASHER

An EXTERNAL TOOTH WASHER is a locking washer with radial teeth formed around its outer edge. It may also be referred to as an external tooth lock washer. When tightened, the external teeth engage with the screw head, nut, and workpiece surface, increasing contact friction and providing auxiliary anti-loosening performance as well as improved electrical grounding contact.

Product Name: EXTERNAL TOOTH WASHER / External Tooth Lock Washer
Product Structure: Radial teeth arranged around the outer edge of the washer
Primary Functions: Provides auxiliary anti-loosening, increases friction, and establishes metal-to-metal contact
Applicable Fasteners: Screws, bolts, nuts, and mechanical assemblies
Inner Diameter: Selected according to the size of the matching screw or bolt
Outside Diameter: Standard dimensions or as specified by drawing
Number and Profile of Teeth: Manufactured according to washer size, contact surface, and engagement requirements
Materials: Spring steel, carbon steel, stainless steel, or other specified materials
Heat Treatment: Can be evaluated according to hardness, elasticity, and fatigue-resistance requirements
Surface Treatments: Zinc plating, nickel plating, black oxide, passivation, or other specified finishes
Applicable Standards: DIN, JIS, ANSI, or customer-specified standards
Production Methods: Stamping, forming, and heat treatment
Packaging: Bulk packing, bag packing, or box packing

External Teeth Increase the Engagement Area

The teeth are distributed around the outer edge of the washer, creating a wider contact area. This makes the washer suitable for assembly locations where the screw head or nut has a relatively large bearing surface.

Provides Auxiliary Anti-Loosening Performance

When compressed, the external teeth can bite into the mating surface and increase frictional resistance, helping reduce the possibility of reverse rotation under general vibration conditions.

Provides Elastic Contact Pressure

The teeth deform under compression and generate spring-back force, helping maintain contact pressure and compensate for minor gaps or surface irregularities.

Helps Improve Electrical Grounding

The external teeth can penetrate localized paint, oxide layers, or surface coatings to establish metal-to-metal contact between components, making them suitable for enclosures, electrical control equipment, and grounding assemblies.

Suitable for Various Equipment and Assemblies

EXTERNAL TOOTH WASHERS are commonly used in electronic and electrical equipment, machinery, automotive and motorcycle components, home appliances, enclosures, and sheet metal structures. Because the teeth may leave marks on the mating surface, suitability should be confirmed before use on visible or decorative surfaces.