ForgeFix TechFast Window Baypole screws are self-drilling screws which are suitable for joining bay window and other metal reinforced PVCu sections. They have a wafer head with TORX® compatible recess. Their No.3 drill tip allows self-drilling into steel up to 4mm.These screws are fire resistant and are protected by 'Elementech' corrosion resistant coating, which has been salt spray tested to 1000 hours. They comply with EU safety, health and environmental requirements. TX25 impact bit included.