Black 403 Grade Martensitic Semi Magnetic Stainless Steel Torx head decking screws for fascia board / decking / composite decking. 403 Grade Non Corrosion and black coated for discrete installation. Countersunk Torx head. 8mm Head Diameter Used for decking, fencing, fascia boards, external use. Lengths available 40mm / 50mm / 60mm / 70mm / 80mm.