The multiple shear off screw principle

One of the basic improvements of the 2nd generation of the M-series is the multiple shear off screw. It clamps the respective conductor cross section with an appropriate torque moment using an inner and outer hexagon. At the same time this shortens the installation times substantially.

The principle of how these new screws work is described below.

1. The screw has an inner and outer hexagon. Both are related to the various shear-off-areas of the screw and their different torque moments.

2. The torque moments follow the rule that large conductor cross sections need high torque moments and smaller cross sections need lower torque moments.

3. The installation instructions describe the use of both hexagons and of the various center rings, for the respective conductor types.

4. The installation is substantially easier in comparison with the telescopic screw, as each screw only has to be tightened and sheared-off once.