Also known as sheet metal or tapping screws, these hardened, zinc plated 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. Metal screws are also available in stainless steel. 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.