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.
SHEET METAL SCREWS HAVE SHARP THREADS THAT CUT INTO MATERIALS SUCH AS: