Inner cam faces
Paired ramps create the mechanical wedge-locking action.
Authorised distributor
Nord-Lock wedge-locking solutions
Preventing rotational bolt loosening through geometry, even under severe vibration and dynamic loading.
When safety really matters
No more loose bolts.
Nord-Lock washers use paired cams and surface serrations to secure a bolted joint against rotational loosening.
The wedge-locking effect is created by geometry rather than friction alone. If the fastener attempts to rotate loose, the cams force the bolt tension to increase, helping the joint stay secure.
- High resistance to vibration-induced rotational loosening
- Reliable locking for safety-critical bolted joints
- Locking action based on cam geometry rather than friction alone
- Helps preserve clamp load and joint integrity
- Straightforward visual inspection and traceability
Wedge-locking principle
A two-piece washer pair that locks by tension.
Each pair has cams on the inner faces and radial serrations on the outer faces.
The serrations grip the fastener and joint surfaces. When loosening rotation begins, movement is directed between the cams. Because the cam angle is greater than the bolt thread pitch, that movement raises the bolt tension before the joint can rotate loose.
Outer serrations
Radial teeth engage the bolt head or nut and the clamped material.
Cam angle > thread pitch
Attempted loosening increases tension, opposing the rotation.
Secure preload
The joint remains locked even during vibration and dynamic loading.
Performance validation
Junker vibration testing.
The DIN 65151 vibration test compares how bolted connections retain clamp load under severe transverse movement.
Conventional locking approaches can lose preload quickly. The supplied Nord-Lock reference shows the wedge-locking pair retaining clamp load and producing a distinct rise in tension as untightening begins.
See real applications →DIN 65151Clamp load retained under vibration
Wedge-locking geometry helps stop rotational loosening before the joint separates.
Product selection
A solution for each joint.
Final selection depends on joint design, environment, material and loading.
01Core range
Original Washers
Wedge-locking washers for secure bolted joints exposed to vibration and dynamic loads.
View product 02Multi-functionX-Series Washers
A combined locking and spring effect for applications where settlement or relaxation may occur.
View product 03Steel constructionConstruction Washers
Wedge-locking washer pairs for compatible structural steel bolt and nut systems.
View product 04Heavy vehiclesWheel Nuts
A captive washer and nut assembly for compatible flat-faced steel wheel rims.
View product 05Large boltsSuperbolt Tensioners
Multi-jackbolt tensioning that produces high preload using compact hand tools.
View product 06Pivot pinsExpander System
An expanding pivot-pin system designed to eliminate movement in worn lug bores.
View product 07CouplingsEZ Fit Expansion Bolts
Zero-clearance expansion bolts for rotating flanges and shaft couplings.
View productIndustrial applications
Made for environments where failure is not an option.
Nord-Lock solutions are used across transport, infrastructure, processing and heavy industry.
Explore applications →01Rail
02Construction
03Manufacturing
04Oil & Gas
05Mining
06Power Generation
How it works
Cam geometry turns movement into locking force.
Tighten
Radial teeth grip the fastener and joint surface.
Pair
The two washers remain locked together at the cam faces.
Counter movement
Attempted loosening forces the cams to climb against one another.
Hold tension
The wedge effect increases bolt tension and resists rotation.
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