Nord-Lock Wedge-Locking Washers — Anti-Vibration Bolting

How Nord-Lock Wedge-Locking Technology Works

Nord-Lock Group is a global leader in secure bolted joint technology. Through Fabory’s partnership with Nord-Lock, customers can access reliable wedge-locking solutions designed to improve the safety, efficiency and service life of critical bolted connections.

Developed in 1982, the original Nord-Lock® wedge-locking technology secures bolted joints exposed to severe vibration and dynamic loads. Unlike conventional locking methods that rely on increased friction, Nord-Lock washers use tension to prevent the bolt or nut from rotating loose.

The system consists of a pre-assembled pair of washers with cams on the inside and radial serrations on the outside. During installation, the serrations grip the surfaces beneath the bolt head and nut, while movement is permitted only between the internal cam faces.

Because the angle of the cams is greater than the pitch of the bolt thread, any attempt by the fastener to rotate loose creates a wedge effect. This increases tension in the joint and prevents further rotation, helping maintain the required clamping force even under demanding operating conditions.

When to Use Nord-Lock Washers

Nord-Lock washers are designed for bolted joints where maintaining a secure connection is critical. They are particularly suitable when:

Vibration and dynamic loads could cause conventional fasteners to loosen
Safety-critical joints require reliable protection against rotational loosening
Regular maintenance calls for a reusable locking solution
High clamping force must be maintained throughout the service life of the joint

Typical applications include wind turbines, mining equipment, industrial presses, rail infrastructure, truck chassis and heavy steel construction.

Learn more about bolt locking methods in our technical guide to fastener locking.

Product type	Material	Surface treatment	Recommended applications	Reusable	Nord-Lock size range
Steel – Regular Outer Diameter	Steel, EN 1.7182	Delta Protekt® zinc-flake coating	General steel applications	Yes, subject to inspection before reuse	M3–M130
Stainless Steel A4	Stainless steel A4, EN 1.4404	Uncoated	General stainless-steel applications in non-chloride and non-acidic environments	Yes, subject to inspection before reuse	M3–M80
Steel – Enlarged Outer Diameter	Steel, EN 1.7182	Delta Protekt® zinc-flake coating	Flanged fasteners, oversized or slotted holes, sensitive surfaces and soft materials	Yes, subject to inspection before reuse	M3.5–M36

Product sizes and availability may vary by market.

Nord-Lock Washers Available from Fabory

Choose from three Nord-Lock wedge-locking washer ranges for secure bolted joints exposed to vibration and dynamic loads. Select the material and outer diameter that best suit the fastener, contact surface and operating environment.

Nord-Lock Steel Washers with Regular Outer Diameter

Manufactured from steel and protected with a Delta Protekt® zinc-flake coating, these washers are suitable for general steel applications where vibration or dynamic loads could cause conventional fasteners to loosen.

View steel Nord-Lock washers

Nord-Lock Stainless Steel A4 Washers

These uncoated A4 stainless steel washers provide a wedge-locking solution for general stainless-steel applications where additional corrosion resistance is required.

View stainless steel Nord-Lock washers

Nord-Lock Steel Washers with Enlarged Outer Diameter

The enlarged outer diameter improves load distribution and is designed for applications involving flanged fasteners, oversized or slotted holes, sensitive contact surfaces and soft materials.

View enlarged Nord-Lock washers

Frequently Asked Questions

What are Nord-Lock wedge-locking washers?

Nord-Lock wedge-locking washers secure bolted joints using tension rather than increased friction. They are supplied as a matched pair, with cams on the inside and serrations on the outside. Because the cam angle is greater than the pitch of the bolt thread, any attempt at rotational loosening creates a wedge effect that maintains preload and prevents further rotation, even under severe vibration and dynamic loads.

How do Nord-Lock washers differ from standard spring washers?

Standard spring washers rely primarily on friction and spring action to resist loosening. Nord-Lock washers secure the joint through tension. Because the cam angle is greater than the bolt-thread pitch, attempted rotation creates a wedge effect that increases tension in the joint and prevents the fastener from rotating loose. Nord-Lock washers have demonstrated their locking performance in Junker vibration testing according to DIN 65151 and ISO 16130.

What Nord-Lock sizes and materials does Fabory offer?

Fabory offers approximately 170 Nord-Lock products across three main variants: steel washers with a Delta Protekt® zinc-flake coating and regular outer diameter, available in the manufacturer’s M3–M130 range; A4 stainless steel washers with regular outer diameter, available from M3–M80; and Delta Protekt®-coated steel washers with an enlarged outer diameter, available from M3.5–M36. Individual sizes and availability may vary by market.

Are Nord-Lock washers reusable?

Yes. Nord-Lock washers can normally be reused, provided both washers in the pair are thoroughly inspected before reinstallation. The cams, serrations and washer surfaces should be checked for wear, corrosion or damage. Damaged or excessively worn washers should not be reused, and the pair must always be reinstalled cam face to cam face.

In which industries are Nord-Lock washers commonly used?

Nord-Lock washers are used in safety-critical and maintenance-intensive applications across industries including wind and power generation, mining, rail infrastructure, transport, heavy machinery, steel construction and process industries. They are particularly suitable for bolted joints exposed to severe vibration, dynamic loading or repeated maintenance.

Nord-Lock Wedge-Locking Washers — Vibration-Resistant Bolting Solutions