100 x TechFast Sheet to Sheet Roofing Screw 6.3 x 22mm 100 x TechFast Sheet to Sheet Roofing Screw 6.3 x 22mm Roofing Stitching Screws (For Sheet to Sheet) Washered Hex Head Screw. Steel Sheet to Steel Sheet Head: Hexagon with Self-Drilling Point Finish: New ‘Elementech’ coating for superior anti-corrosion – salt spray tested to 1000 hours -Self-drilling point enables improved and speedy insertion when joining sheets -Designed specifically for joining cladding sheets together -Can join up to three sheets of 0.7mm thickness -The 16mm rubber washer beneath the aluminium flange expands under pressure and forms a permanent weather-seal
