Cleveloc & All Metal Self Locking Nuts


The Cleveloc nut is a low cost one-piece self-locking nut with superior locking and re-usability characteristics. The locking collar is an integral part of the nut and is formed into a geometrically developed ellipse. This provides two locking elements of consistently uniform shape and thread contour which permit the bolt threads to engage smoothly during assembly.

There are no thread interruptions or pitch errors to react unfavourably or to induce galling on the bolt threads. The two locking elements utilize most of the collar portion of the nut and the threads that come within its depth. The elliptical form of the locking collar with its distribution over wide areas of the locking pressure, ensures a high fatigue life with necessary flexibility to give consistent performance and dependability in service. These locking elements are designed to create gradually increasing areas of pressure and friction on the bolt threads.

Further tightening forces the locking elements to engage more fully with the bolt threads and this increasing resistance to the entry of the bolt brings the full length of the nut threads into close contact with the working faces of the bolt threads. Further friction is created and both forces combine to give a smooth, progressive and increasing self-locking action.


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Specification : DIN 980, DIN 6925, DIN 6927 & Customer Prints

Size Range :  M5 to M33 (Metric Series) 1/4″ to 1 1/4″ (British/Unified Series)

Finishes Available : Bright Zinc, Zinc Blue, Zinc Yellow, Zinc Black, Zinc Green. Hexavalent or Trivalent chrome.


  • All metal Lock Nut
  • Superior Locking
  • High Re-usability
  • Uniform Performance
  • High Temperature Application (250° C)



Rugged-Economic-One-Piece Nuts : Precision formed and processed on special-purpose plant for competitive costs. Unaffected by water, oil, a wide range of solvents and corrosives, or temperatures upto 250’C. Cleveloc nuts have a permanent self-locking action which effectively withstands shock, vibrations, and repeated load reversals.

Dependable Locking Properties :

The closed stress path in the locking portion of the nut together with the advantageous distribution of locking pressure over comparatively large areas, provides a locking device with an extremely high fatigue life.

High Re-Usability :

The stress within the locking device when in service is distributed over the two locking elements which represent a comparatively large area. Consequently, ‘local stresses’ are only a fraction of those of slotted type all-metal stiffnuts. Result : an infinitely long service life of many re-usals.

Fast Trouble-Free Assembly :

All the threads within the nut body are free running-there is no deformation of the hexagon form, and galling is totally eliminated by the elliptical design of the locking collar which prevents thread interruptions or pitch errors. Easily engaged, a spanner or power tool will tighten the Cleveloc nut and its smooth progressive locking action is effective at any required setting.

Lower Assembly Torques :

Pre-lubricated as a standard finish with a special base lubricant, Cleveloc nuts produce required bolt clamping forces at approximately ‘ 75 ‘, only of the assembly torque required for untreated nuts. This permits the use of smaller and lighter power tools with reduced operator fatigue, tooling costs and power consumption. Uniform Clamping Loads – A desirable feature achieved by the coating of lubricant provided. This finish effectively reduces the widely varying degrees of friction normally evident between the mating faces during assembly. Pre-lubrication provides more reliable and consistent results with torque spanners under various bolting conditions.

Interchangeable :

Cleveloc nuts are equally effective with high or low limit bolt threads, and can be safely changed from high to low limit bolts during maintenance or overhaul.

All Threads Load Bearing :

The two locking elements are an integral part of the nut and all threads are fully load supporting.

Easy to Identify :

Cleveloc self-locking nuts can be easily identified in the stores and on the production line by their distinctive shape and appearance.