The Evolution Hex Head Self-Drilling Tek 3 Screws are designed for fixing cladding/roofing applications to hot/cold rolled purlins/rails and fastening liner panels and general components to steel. They have a single, coarse thread form (Tek 3) and are made from carbon steel with a AISI C1022 material grade. The drilling capacity is 1.2-4.0mm and the recommended drill speed is 1500-2500 RPM.