These Forgefix Tec Fix Roofing Screws are self drilling, winged and have countersunk heads.
Suitable for use when fixing timber to light section steel, thickness from 1.5mm to 4.0mm.
Self-drilling screws have a drill-shaped point to cut through the substrate to eliminate the need for drilling a pilot hole. They are designed for use in soft steel or other metals.
The Phillips screw has four simple tapered slots. It is designed so that a Phillips tip screwdriver can turn a Phillips screw with increasing torque. When the torque gets to be too strong for the tip then the screwdriver tip winds itself out of the screw thus preventing over-tightening and or damage to the screw head. The countersunk heads are designed to sink flush with substrates to leave a smooth surface finish.