General description The Forgefix TechFast Hex Head Roofing Screws are heavy-duty self-drilling screws designed for securely fixing steel sheets and cladding to heavy steel purlins. With a size of 5.5 x 35mm, these screws provide a reliable and weatherproof connection, making them ideal for both professional and DIY projects involving steel construction. Technical specifications Size: 5.5 x 35mm Pack quantity: 100 screws Material: Steel with Elemtech coating Corrosion resistance: Salt spray tested for 1000 hours Fire resistant Compatibility and accessories Compatible with steel sheets and cladding for heavy steel purlins Suitable for steel thicknesses between 6mm and 12.5mm Supplied with rubber washers for sealing Installation Use a compatible drill or screwdriver to drive the screw into steel surfaces Ensure the rubber washer is properly seated to create a weatherproof seal Install screws at appropriate intervals for secure fastening Usage Ideal for fixing steel sheets, cladding, and