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What is a Turnlock Fastener quarter turn?

Turnlocks are fasteners that are an easy and fast solution to open and close panels with a minimum effort.

However, these aren't fragile closing mechansims.

Turnlocks are resistant to vibrations, meaning that the turnlock quarter turn fastener will not open by itself but by manipulation.

A turnlock assembly gives you an easy and secure locking solution that's very easy to operate.



A turnlock assembly needs at least 3 parts:

  • the stud
  • the retaining washer
  • the receptacle

Some series like the HGR needs also a grommet and a retaining ring.

Another series such as the LMH or the LEA you can use a grommet INSTEAD of a retaining washer, which makes the assembly much easier to install.

In order for the turnlock assembly to work, there needs to be a spring function involved. Depending on the series, this spring function will either be in the stud or in the receptacle.


Turnlocks connect components under an elastic preload. The tensile load of each assembly in the catalogue was reached after overcoming the springelement generated preload. This is unlike threaded fasteners, turnlocks do not rely on the elasticity of joint and fastenermaterials to accomplish preload. The stud assembly or receptacle was designed with a springelement. This allows the repeated application of controlled preload with assured reliability over a high number of cycles.

How does it work?

When the studassembly is rotated, the stud cross pin rides up the cam causing a controlled joint preload to be applied. This can be done by rotating the stud 90 degrees. At this point a positive mechanical stop is reached and the crosspin falls into the locking detent. This mechanism makes sure that there is a near perfect resistance to vibration induced loosening of the assembly assured.