Designed to attach sheet metal (max 0.8mm) to timber. Once installed the EPDM washer prevents water ingress. Exterior plating gives a reliable and durable corrosion resistant coating which resists over 500 hours salt-spray.Exterior plating gives a reliable and durable corrosion resistant coating which resists 500 hours salt-spray. Single slash point to reduce torque and the risk of timber splitting at low edge distance.