.Self-Drilling Screw, #12 x 3 in, Zinc Plated Steel Flat Head Phillips Drive, 100 PK A self-drilling screw, or tek screw, is similar to a sheet metal screw, but it has a drill-shaped point to cut through the substrate to eliminate the need for drilling a pilot hole.
. Especially useful in metal-to-metal or where heavy duty fastening is required. A machine screw, also called a stove bolt, is generally a smaller fastener threaded the entire length of its shank.