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a premium stainless steel wheel nut distributed globally. The Checklock SQ® has two handles that, when squeezed together with the fore finger and thumb, loosen the two coils enough to allow room for two adjacent nuts to pass through

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Primary Functions

The primary functions of Checklock SQ® are to:.

  • Retain wheel nuts to lower the likelihood of them loosening
  • Greatly reduce the likelihood of wheel nuts backing away completely from the wheel hub
  • Provide a clear commitment to roadworthiness and professionalism to other road users, customers, health and safety, road and transportation associations such as DfT, HMRC Customs and Excise, VOSA, HSE, FTA and RHA
  • Can comfortably incorporate a wheel overheating indicator function

Primary Benefits

The primary benefits of fitting Checklock SQ® are:

  • Improved safety of fittings where nuts are a critical structural component, such as on vehicle wheels and industrial/commercial structures
  • Much improved vehicle safety through avoiding potentially severe road accidents resulting from loose wheel nuts or wheel detachment
  • Simple to fit, with no additional tools required, to help the reduction in maintenance time and costs
  • Reduction in vehicle downtime
  • Improved professionalism, roadworthiness and safety related company image or reputation
  • Cost effective and easy solution to implement
  • High quality premium stainless steel reuseable product


This product has applications in various sectors


Examples of applications


Sizes Available

We stock various sizes for this product.

Checklock SQ® are sized by the corresponding measurement (in millimetres) across the flats of the hexagonal nut fitting, along with a measurement (also in millimetres) of pitch circle diameter (PCD). Current sizes available* include (in mm):

  • 17mm, 139.7 PCD (4-Stud wheel)
  • 19mm, 139.7 PCD (4-Stud wheel)
  • 19mm, 165.1 PCD (5-Stud wheel)
  • 24mm, 205 PCD (6-Stud wheel)
  • 24mm, 245 PCD (6-Stud wheel)
  • 24mm, 275 PCD (8-Stud wheel)
  • 27mm, 165.1 PCD (6-Stud wheel)
  • 27mm, 205 PCD (6-Stud wheel)
  • 27mm, 245 PCD (6-Stud wheel)
  • 27mm, 275 PCD (8-Stud wheel)
  • 30mm, 275 PCD (8-Stud wheel)
  • 32mm, 225 PCD (10-Stud wheel)
  • 32mm, 335 PCD (10-Stud wheel)
  • 33mm, 285 PCD (10-Stud wheel)
  • 33mm, 335 PCD (10-Stud wheel)
  • 38mm, 285 PCD (10-Stud wheel)
  • 38mm, 335 PCD (10-Stud wheel)

New sizes of Checklock can be developed in a matter of a few weeks, so if your desired size is not included in the list please contact us with an enquiry. If you have any doubts please get as much information as possible and then contact us for assistance in establishing the correct Checklock SQ® for your application.

* Availability depends on current stock levels, dictated by demand.

Convert your measurements with our simple calculator.


Standard Colours

The Checklock SQ® comes in a standard uncoated stainless steel grey.


Recommended Fitting


Material Grade

Checklock SQ® is made from a high grade, premium stainless steel that will not corrode, rust or stain with water, as ordinary steel does. The product has a very long life and can be reused/refitted, ensuring fantastic value for the end user.



For further information contact Checkpoint Safety