Introduction to Bi-Fix
The Bi-Fix Quarter Turn Fastener is used for securing panels and components
where accessibility is important. The special characteristic of the Bi-Fix
Quarter Turn Fastener is its quick and simple closure. A 90º turn of the stud
unlocks the connection (Fig 2), finger pressure onto the head of the stud
re-clicks the fastener into the locked position (Fig 1). The Bi-Fix Quarter Turn
Fastener can be used wherever two elements have to be fastened and detached in a
quick and safe manner. Bi-Fix is ideal for any application where panels, doors
or hatches are continually opened or removed for maintenance or security.
Manufactured from quality materials, they are robust and easy to operate.
The Bi-Fix Quarter Turn Fastener consists of 3 parts:
- The Stud, which is located in the loose panel.
- The Washer, which is used for retention of the stud and vibration resistance.
- The Spring Clip, which is installed permanently into the shell framework, and
is designed to ensure that the stud is ejected automatically when turned 90º.
The Bi-Fix Quarter Turn Fastener is manufactured in 3 size series, 8mm, 11mm or 16mm.
Essentially, the stud is held captive in the loose panel by a washer, the
function of which is to seal the hole of the fixed part and to avoid vibration.
For each size series there are different thicknesses of washers available. They
consist of Neoprene and they can be used in a temperature range of -40 ºC to
+90 ºC. Neoprene is also resistant against UV rays and most industrial fats and oils.
Determining Washer Thickness
To determine thickness of the washer required (dimension T), add thickness of
the fixed part (dimension B) to the free space between panels (dimension C), and
then add 25%. Choose standard washer nearest to this dimension. Thickness of the
washer T = (B + C) x 1.25. Please note that the thickness of the washer includes
the free space. As shown in the drawing, the assembly is solidly fixed and
resists vibration and lateral movement.
Retaining for applications exceeding 90 ºC
When Bi-Fix is to be used at temperatures exceeding 90ºC, a conical wire spring can be used instead of the washer.
The grip length (P Dimension) is critical and is always measured from the
underside of the head of the stud to the top surface of the clip. This includes
The "P" Dimension - Determining Total Panel Thickness
To determine the correct stud length, the "P" dimension has to be chosen according to the following example
P = A + B + C