Star Washer External

Product Introduction

• Standard Name: External Tooth Lock Washer / Star Washer.

• Common Names: External Tooth Lock Washer, External Tooth Washer, Serrated Washer.

• Product Definition: A locking washer featuring serrated teeth along its outer edge. During installation, the tooth tips bite into the surface of the connected components, providing mechanical locking to prevent nut or bolt head loosening due to vibration. Compared to internal tooth types, its external serrations offer a larger engagement area.

Star Washer External Key Features

• External Tooth Design: The outer ring features twisted teeth that engage with the material surface

  during compression, providing strong frictional locking, resisting vibration and loosening, and offering

  superior grip compared to internal teeth.

• Materials and Coatings: Commonly carbon steel with zinc plating (ZP), black anodizing, or other finishes

  providing basic rust protection; conforms to standards such as DIN 6797 A and ASME B18.21.1.

• Ring Structure: A circular flat plate with outward-protruding external teeth, suitable for use under the nut,

  enhancing the engagement.

• Various Sizes: Inner diameter M3-M36, standard tooth count and height, commonly used in vibration

  environments.

• Advantages: Strong anti-loosening effect, suitable for soft materials or coated surfaces, but may damage

  visible surfaces.

Working Principle

• Compression Installation: Placed under the nut, the teeth are compressed and deformed during tightening.

• Engagement Generation: The external teeth engage with adjacent surfaces (usually the material under

  the nut), generating friction and mechanical locking to maintain the clamping force.

• Vibration Resistance: Under vibration, the teeth prevent reverse rotation; the coating provides mild

  corrosion protection.

• Load Distribution: Evenly transmits pressure, preventing loosening; the principle involves elastic

  deformation, tooth engagement, and frictional grip.

Product Applications

• Electrical Connections: Secure grounding or terminals; external teeth provide reliable conductivity

  and prevent loosening.

• Automotive and Machinery: Assemble engines, chassis, or vibrating components to resist high vibrations.

• Sheet Metal Processing: Join thin sheets or coated metals; tooth engagement enhances grip.

• Industrial Equipment: Secure machine tools, pumps, valves, or conveyor systems.

• Construction Engineering: Connect steel structures or pipes, providing additional anti-loosening

  protection.