External Tooth Lock Washer

External Tooth Lock Washer — Product Introduction

The external tooth lock washer is a locking washer with multiple tooth-shaped protrusions formed on its outer circumference; common standards include GB/T 862.1 and DIN 6797. It works by having the external teeth embed into the surface of the connected parts, increasing contact friction, thereby effectively preventing bolts and nuts from loosening under vibration or impact. The external tooth lock washer is commonly made of spring steel (such as 65Mn, 60Si2Mn, and steel 70); after quenching and tempering the hardness is generally controlled at HRC 40–50. When corrosion resistance is required, stainless steel (such as SUS304 and SUS316) or ordinary carbon steel with surface treatments such as galvanizing or black oxide can also be selected. This product is widely used at various threaded connection points that require reliable locking.

I. Product Features

• External tooth structure: Multiple tooth-shaped protrusions are evenly distributed around the outer ring; after installation, the tooth tips bite into the surface of the connected parts, forming multi-point locking.
• Excellent elasticity: Made of spring steel, after heat treatment it retains good elasticity and recovery force, keeping the locking effect continuously stable.
• Diverse materials: Spring steel, stainless steel, or carbon steel can be selected to meet different requirements for strength, corrosion resistance, and cost.
• Moderate hardness: The hardness of common spring steel materials is controlled at HRC 40–50, which locks effectively while avoiding excessive damage to the mating surface.
• Complete specifications: Suitable for various thread sizes such as M2–M20, and can be used together with bolts, screws, and nuts of different diameters.
• Optional surface treatment: Black oxide, phosphating, galvanizing, Dacromet, etc., improving corrosion resistance and appearance quality.

II. Product Advantages

• Reliable locking: The external teeth embed into the workpiece surface, forming mechanical locking, with a better anti-loosening effect than ordinary flat washers and some spring washers.
• Suitable for soft materials: The tooth structure can bite into softer surfaces such as aluminum, copper, and plastic, especially suitable for light-metal or non-metallic connections.
• Convenient installation: Placed directly on the bolt or screw for use, no special tools required, suitable for fast assembly.
• Good electrical conductivity: The metal tooth tips penetrate the oxide layer, improving conductive contact, often used in electrical connections.
• Cost-effective: Simple structure, mature manufacturing process, low price, suitable for large-scale use.
• Strong versatility: Can be matched with various standard bolts, screws, and nuts; it is a highly versatile anti-loosening element.

III. Application Scope

• Electronics and electrical appliances: Household appliances, instruments and meters, switches and sockets, power terminals, and other screw connections requiring locking and conductivity.
• Automotive industry: Threaded connections at interior trim parts, electrical boxes, wire harness fixing, instrument panels, etc.
• Machinery equipment: Connections in vibrating environments such as small machinery, power tools, office equipment, precision instruments.
• Communication equipment: Metal sheet connections such as chassis, cabinets, connectors, antenna brackets.
• Hardware products: Assembly of door and window hardware, locks, lighting fixtures, toys, etc.
• Other anti-loosening occasions: For any threaded connection requiring low cost, easy installation, and high anti-loosening requirements, the external tooth lock washer can be selected.