The sandwich panel screw for steel is made of Bi-metal. This means that the screw is made of stainless steel and the self-drilling tip of metal. A stainless steel drill point is too soft to drill through steel. That is why a steel drill point was chosen. The screws for mounting sandwich panels on wood are made entirely of stainless steel. Application : For metal, timber.Fastening sandwich panels and various fixtures to 1.5-12 mm steel framingDry indoor, indoor with temporary condensation,outdoor with low pollutionFor reliable fastenings with defined load values