DIN6798

Characteristics of DIN6798 External Tooth Lock Washers

Standardized Design:

As a DIN standard product, DIN6798 external tooth lock washers adhere to strict dimensional and tolerance requirements. This ensures interchangeability with fasteners and consistency in performance across batches, making them suitable for both production environments and replacement applications.

Enhanced Locking Performance:

The external teeth extend outward from the washer’s outside edge, creating a serrated interface that increases friction with the surface. This design greatly reduces the risk of fastener rotation — especially under vibration and dynamic loads — compared to standard flat washers.

Wide Load Distribution:

The washer’s broad surface helps distribute clamping force more uniformly across the contact area. This reduces stress concentration on the substrate and minimizes material deformation or indentation, particularly on soft or coated surfaces.

Durable and High-Strength:

DIN6798 external tooth lock washers are typically manufactured from durable steel grades. Depending on the application, materials can be heat treated or surface coated (zinc-plated, black oxide, etc.) to further improve corrosion resistance and mechanical stability.

Versatile Compatibility:

These washers are compatible with a wide range of fasteners — including hex bolts, machine screws, shoulder bolts, and studs — making them highly versatile in industrial and structural assemblies.

How Does the External Tooth Design Generate Locking Force?

The defining feature of DIN6798 external tooth lock washers is the serrations on the washer’s outer circumference. These teeth are not merely decorative — they serve a functional purpose in enhancing the locking force of the fastened joint.

When a bolt or nut is tightened, the external tooth lock washer is compressed between the fastener head (or nut) and the mating surface. The serrated teeth dig into the substrate materials and the fastener surface, creating a mechanical interlock that increases friction and resists relative motion. This action prevents the fastener from loosening under vibration, shock, and dynamic stress.

The locking force arises from three key mechanisms:

Mechanical Interference: The teeth penetrate micro-irregularities on the surface, creating resistance to rotational movement.

Increased Friction: Serrated contact produces more surface friction than a plain flat washer, which directly opposes fastener turning.

Clamping Pressure Maintenance: The external tooth design helps maintain preload by minimizing slippage between components, keeping the joint secure over time.

Because the teeth engage with both the fastener and the contact surface, this design is especially effective in assemblies where maintaining torque and preload is critical, such as in engines, industrial machines, and heavy equipment.

Does the Number of Teeth Affect Performance?

Yes — the number and shape of teeth on an external tooth lock washer can influence its overall performance in a fastening application.

In general:

More Teeth = Greater Contact Points:

A washer with more teeth offers more individual points of contact with the mating surface. This distributes frictional force more evenly and can increase anti-rotation resistance, especially in softer materials where deeper engagement occurs.

Fewer Teeth = Deeper Bite Per Tooth:

Washers with fewer, larger teeth may penetrate deeper into the surface under the same compressive load. This can improve locking force in harder materials where shallow teeth might not engage as effectively.

Tooth Geometry Matters:

It’s not only the number of teeth but also their angle, sharpness, and spacing that impact performance. Properly designed teeth balance penetration (for grip) and surface preservation (to avoid excessive damage to the substrate).