Type F Thread Cutting Screws - Thread cutting screws are a type of self-tapping screw. They create threads in existing holes in metal, and are often used as fasteners in items that need periodic maintenance. Thread cutting screws are most often used with wood and metal.  Thread cutting screws do not generate the same stress as thread forming screws. Type F thread cutting screws is a thread cutting screw with machine screw thread with blunt tapered point, having multi cutting edges and chip cavities. For heavy gauge sheet metal, aluminum, zinc and lead die castings, cast iron, brass and plastic.