DIN 6795 Grounding Lock Washers (SKK Type): Features, Installation and Electrical Grounding Applications

DIN 6795 Grounding Lock Washers (SKK Type): Reliable Grounding and Anti-Loosening Fastening Solutions

In electrical and industrial systems, maintaining stable grounding connections and securely locking fasteners are critical for operational safety and reliability. DIN 6795 grounding lock washers, also known as SKK grounding washers or puncture washers, are fastening components designed to provide both anti-loosening performance and reliable electrical grounding contact.

These washers are manufactured in accordance with DIN 6795 and SN70093 standards, including specifications commonly used in industrial electrical assemblies, such as those of Siemens. Due to their unique structure and high-strength materials, grounding lock washers are widely used in electrical cabinets, communication equipment, rail transportation, and industrial machinery.

What Is a Grounding Lock Washer?

A grounding lock washer is a specially designed disc-shaped washer used in electrical assemblies to ensure both mechanical fastening security and reliable grounding contact.

The SKK-type grounding washer features:

• Striped or serrated locking surface on one side

• Six grounding claws on the opposite side

• Conical disc structure for elastic tension

When tightened with a bolt or screw, the claws penetrate the surface coating of the connected material, ensuring direct metal-to-metal contact for effective electrical grounding while also preventing loosening of the fastener.

Typical washer sizes range from M2.5 to M20, covering most industrial fastening applications.

Alternative Names and Equivalent Products

Grounding lock washers may also be referred to by several industry names, including:

• SKK grounding washer

• DIN 6795 grounding washer

• SN70093 puncture washer

• K-type grounding washer

• French grounding lock washer

• Grounding butterfly lock washer

These washers are widely used in electrical grounding systems where secure fastening and conductive contact are required simultaneously.

Key Features of DIN 6795 Grounding Lock Washers

Dual-Function Design: Locking and Grounding

The combination of serrated teeth and grounding claws ensures both mechanical anti-loosening performance and stable electrical conductivity.

Strong Surface Penetration

The six claws are designed to pierce surface coatings such as paint or oxidation layers, enabling reliable grounding connections.

Elastic Conical Structure

The disc-spring shape creates an elastic rebound force, maintaining consistent clamping pressure even under vibration or thermal expansion.

Improved Load Distribution

The washer helps distribute the clamping force evenly across the fastening surface, improving joint reliability.

Materials and Surface Treatments

DIN 6795 SKK grounding washers are manufactured using high-quality materials to ensure durability and mechanical strength.

Common Materials

• 65Mn spring steel

• SK5 / SK7 high-carbon spring steel

• SUS304 stainless steel (A2)

• 316 stainless steel (A4)

Heat Treatment

All washers undergo strict hardening and elastic tempering processes to ensure proper spring performance and long service life.

Surface Treatment Options

For carbon steel washers:

• Black oxide coating

• Zinc plating with dehydrogenation treatment

• Zinc-magnesium coating

• Dacromet corrosion-resistant coating

Stainless steel versions may include surface hardening and polishing to enhance durability.

Installation Method for Grounding Lock Washers

Proper installation is essential to achieve optimal grounding and locking performance.

Step 1 – Position the Washer

Place the washer between the bolt head (or nut) and the grounding surface.

Step 2 – Ensure Correct Orientation

The claw side should contact the grounding substrate, allowing the claws to penetrate the surface coating.

Step 3 – Tighten the Fastener

When the bolt or screw is tightened, the claws embed into the substrate, creating secure electrical contact and mechanical locking.

Step 4 – Verify Grounding Contact

Ensure that the washer has fully penetrated the coating layer to establish proper metal-to-metal grounding.

Industrial Applications of SKK Grounding Lock Washers

Because of their excellent grounding and locking capabilities, DIN 6795 washers are widely used in industries that require reliable electrical bonding and vibration-resistant fastening.

Electrical Cabinets and Control Panels

Used to secure grounding wires and terminals inside electrical cabinets and distribution panels.

Communication Equipment

Applied in telecom infrastructure and communication systems to ensure stable grounding connections.

Elevator Systems

Used in elevator control systems and electrical components to maintain safe electrical grounding.

Rail Transportation Equipment

Installed in rolling stock assemblies where electrical grounding and vibration resistance are required.

Water Treatment Equipment

Used in industrial water treatment systems where electrical safety and corrosion resistance are critical.

Advantages of Using Grounding Lock Washers

Compared with conventional washers, grounding lock washers offer several advantages:

• Reliable electrical grounding connection

• Strong anti-loosening performance

• Improved vibration resistance

• Enhanced mechanical reliability

• Long-term corrosion resistance

These features make them essential components of electrical and industrial fastening systems.

Conclusion

DIN 6795 SKK grounding lock washers provide a reliable solution for both mechanical fastening and electrical grounding applications. Their unique combination of serrated locking surfaces and grounding claws ensures secure connections even in demanding industrial environments.

With proper material selection, heat treatment, and installation methods, grounding lock washers significantly improve the safety, reliability, and durability of electrical systems.

Contact Juxin Fasteners

If you are looking for high-quality grounding washers, self-locking washers, or customized industrial fastener solutions, our engineering team is ready to support your project.

JUXIN FASTENERS – 23 Years of Industrial Fastener Manufacturing

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https://www.juxinfasteners.com

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