The Forgefix Hex Head Stitching Screws are designed specifically for joining cladding sheets together. They have a Hex head and a self-drilling point which enables speedy insertion. The rubber washer beneath the aluminium flange expands under pressure to form a permanent weather seal.The screws are zinc plated and have an 'Elementech' coating for superior corrosion resistance, which is spray tested to 1,000 hours. They can join up to 3 sheets of 0.7mm thickness. Specifications:Size: 6.3 x 22mm.Pack quantity: 100.Weight: .589kg.