Thread Diameter 0.112" Head Diameter 0.257" Head Height 0.069" Phillips Drive Size #1 18-8 Stainless Steel provides strength and offers good corrosion resistance in many environments. A Truss head screw has a head with flat underside and a slightly domed top. It has almost no exposed edge. Sheet Metal Screws have deep spiral threads the entire length and with a pointed end. Holds thin metal sheets together. Holds well in wood, Plastic, and Fiberglass. Manufactured from metal. Can be rotated into or out of the object using a screwdriver