The Tolsen 54174 is a self-drilling screw designed specifically for securing metal or aluminum panels, roofs, and facades. These fasteners feature a specialized tip that eliminates the need for pre-drilling, allowing you to work faster and more efficiently on construction projects. Each screw has a diameter of 3.9 mm and a length of 32 mm, providing a reliable hold in thin-walled metallic materials. To ensure long-term durability against corrosion, the screws are zinc-plated, which is essential for installations exposed to the elements. The countersunk head with a Phillips drive allows the screw to sit flush with the surface, creating a neat and professional finish. This pack contains 500 pieces, making it a practical choice for those handling larger surface areas or multiple fastening points.