Self-drilling screws with conventional cutting bit are tapered. Our EJOFAST screws are even significantly sharper. This causes a risk of injury for people. For cable ducts that have been secured with self-tapping screws, there is a risk that power cables could be damaged by the tapered screws.
The remedy is provided by our thread protection sleeves
, which are simply pushed onto the screw points. Michael Hellwig shows how this is done.