Multifunctional wedge-locking

A new evolution in bolt security

There are two main reasons why bolted joints fail: spontaneous bolt loosening and slackening. Traditionally, application design has involved trying to figure out which will have the biggest effect on the joint and choosing a solution to handle that one problem. It is a difficult compromise to make, especially when both could cause application failure.

Expand your bolted joint design possibilities with an excellent security option.

  • Nord-Lock’s multifunctional wedge-locking solution combine unrivaled wedge-effect to prevent spontaneous bolt loosening with an exceptional spring effect to compensate for loss of preload due to slackening, giving total security for those situations in which there can be no compromise.

Bolt security without compromise

Utilizing a unique multifunctional design, Nord-Lock X-series washers offer the highest security against both spontaneous bolt loosening and slackening.


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A new dimension of safety

Upon tightening the fastener, the washers flatten and the serrations engage the contact surfaces. Since the cam angle (α) is greater than the thread pitch (β), the wedge-locking effect will prevent any rotation of the fastener. Directly after tightening, the joint settles and the fastener sinks into the surface material. The washers immediately deflect and the spring effect (Fs) counteracts the slackening movement of the bolt, thereby preventing loss of preload on the joint.

These multiple functions continuously act on the bolted joint to maintain preload and prevent spontaneous bolt loosening — serving as an effective solution for vibration, dynamic loads, settlement and relaxation.

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Benefits throughout your application’s lifespan

Below you find a selection of advantages with Nord-Lock multifunctional wedge-locking solution.


  • Simplify design for demanding applications with a single solution that secures against both spontaneous bolt loosening and slackening.


  • Save time with quick and easy installation using standard tools.


  • Achieve increased operational reliability while significantly reducing the risk of unplanned production stops, accidents, and warranty claims.
  • Invest money and time in profit-generating tasks rather than retightening procedures.


  • Decrease maintenance time with simple disassembly.
  • Save time and money with a reusable solution, especially in industries with difficult access to the bolted joint.
  • Nord-
Lock personnel performs over 10,000 live Junker vibration 
tests around the globe every year.

Proven in Junker vibration test

The Junker test, according to DIN 65151, is considered the most severe vibration test for bolt connections. The test exposes the joint to transverse movements underneath the bolted head/nut, while continuously measuring the clamping force.

The Junker test shows that Nord-Lock’s wedge-locking function safely secures the bolted connection, which is verified through the clear increase in tension during untightening. The Nord-Lock X-series kept the highest initial tension thanks to its additional spring effect.

Would you like to learn more about the performance of Nord-Lock X-series washers? Contact your nearest representative through 
Contact us.