Wedge-Locking Solutions - Prevent Bolts From Loosening

Nord-Lock created the original wedge-locking technology that secures bolted joints, even when exposed to severe vibration and dynamic loads. It is impossible for our products to loosen unintentionally due to the wedge created underneath the bolt head and nut.


How it works


When a bolt is tightened, the serrations on the washers are embedded into the mating surfaces. As the cam angle ‘α’ is greater than the thread pitch ‘β’, a wedge-effect is created, preventing the bolt from rotating loose.

A pair of washers for maximum safety

Nord-Lock bolt securing solutions consist of a pair of washers with cams facing each other and serrations gripping the mating surfaces. They use camgeometry to effectively prevent the bolt from vibrating loose. A hot melt adhesive is used to assemble the washers in pairs. The ingredients of the adhesive meet the compositional requirements of the American Food & Drug Administration regulations 21 CFR 175.105 “Adhesives”.

Tension prevents bolts from rotating loose

Think of the bolt as a spring. Turning the fastener during tightening stretches the bolt like a spring, creating the required clamp load to hold the parts together. Nord-Lock washers secure bolted joints by increasing this clamp load if the bolt tries to rotate loose.


  • Nord-Lock original washers secure bolted joints exposed to severe vibration and dynamic loads
  • Available in a wide range of materials to suit use in general steel and stainless steel applications, and in corrosive, acidic and high-temperature environments
  • Locking function not affected by lubrication - Achieves accurate preload with defined and uniform friction 
  • Available in a wide range of sizes (metric and imperial)
  • Designed for bolts up to and including property class 12.9 (steel) and A4-80 (stainless steel)
  • High corrosion resistance (minimum 1,000 hours in salt spray test according to ISO 9227) for steel washers
  • Reusable (depending on conditions of use)
  • Custom sizes upon request


Nord-Lock washers cannot loosen unintentionally as a wedge-effect is created underneath the bolt head/nut. Our extensive range includes washers in various materials and sizes.

Nord-Lock washers are available in two outer diameters — standard and enlarged. Washers with an enlarged outer diameter (SP washers) are ideal for use on large holes, sensitive surfaces and soft materials.  Nord-Lock SP washers suit flanged bolts/nuts for optimum load distribution.

Tapped holes


Through holes

Stud bolts

When mating surfaces are harder than the washers, Nord-Lock may not be used

Large slotted holes or soft underlying surfaces