M5 to M20 Internal Tooth Lock Washer

The M5 to M20 Internal Tooth Lock Washer is a type of locking washer designed to prevent nuts, bolts, or fasteners from loosening due to vibration or torque. Its internal teeth (pointing inward) dig into the mating surface and the fastener, creating increased friction and resistance to rotation.

Key Features

Internal Teeth: Sharp, radially inward-facing teeth provide a biting action against the fastener and mounting surface.

Material: Typically made from hardened steel (carbon or stainless steel) for durability and spring-like properties.

Load Distribution: Helps distribute clamping load evenly while resisting loosening.

Reusable: Often reusable, though performance may degrade after multiple installations.

Applications

Automotive (engine components, suspension systems)

Machinery (pumps, motors, gearboxes)

Aerospace and industrial equipment

Electrical enclosures and high-vibration environments

Installation Tips

Place the washer between the fastener (nut/bolt head) and the mounting surface.

Ensure teeth face toward the surface (some designs may vary; follow manufacturer guidelines).

Tighten the fastener to the recommended torque—the teeth will embed slightly for a secure grip.

Standards & Sizes

Complies with ANSI B18.21.1, DIN 6797, or other industry standards.

Available in various sizes (metric/imperial) to match bolt diameters.

Advantages Over Other Lock Washers

Better grip on small fastener heads compared to split washers.

Reduced risk of surface damage vs. external tooth washers (which grip externally).