The ZXL Steelbinder Self-Drilling Metal Roofing Screws are engineered for precision and durability, providing a secure connection for metal roofing panels and siding to steel structures. Featuring a #12 Diameter and a 5/16 Cupped HWH design, these self-drilling fasteners effortlessly penetrate steel up to .210 inches in thickness with no point walking. These screws are cupped HWH ZAMAC Zinc-Aluminum Alloy that provides lifetime protection against red rust on the head. You can trust that these screws won't chalk or fade, preserving the aesthetics of your building. Perfect for residential, commercial, and agricultural applications, these screws feature a self-drilling tip that streamlines installation and a bonded EPDM washer to ensure long-lasting, watertight performance. Designed to resist the harshest elements, ZXL screws deliver superior corrosion protection and strength.