Also known as sheet metal or tapping screws, these hardened, 18.8 Stainless Steel screws, available in pan, truss or flat phillips or square drive as well as indented hexagon washer heads. Metal screws are used in all light sheet metal work in all kinds of applications and products. They are used to join sheet metals, metal to wood and to join other types of soft and/or thin unthreaded materials. These screws tap their own threads and are not intended to be disassembled often. Stainless steel for exterior applications where corrosion resistance is required.