General description The Forgefix TechFast Hex Head Roofing Screws are specifically designed for fixing cladding and sheet steel to heavy section steel purlins ranging from 6.0mm to 12.5mm. These screws feature a hex head, are self-drilling, and include a rubber washer that expands under pressure to create a permanent weather seal. Technical specifications Size: 5.5 x 80mm Pack quantity: 50 MPN: TFHH5580 EAN: 5028485100447 Corrosion resistance: Zinc plated with 'Elementech' coating, salt spray tested to 1,000 hours Other information