A Hex Head Self-Drilling Screw is a fastener designed for efficient drilling and fastening in a single step, eliminating the need for a pre-drilled hole. These screws are equipped with a drill point at the tip, allowing them to cut through materials like metal, wood, or plastic without requiring a pilot hole. best roofing sheet in surat. best upvc sheet in Surat. Best hex head screw in surat. mechanical ventilation. Best mechanical ventilation in surat.