Self-Tapping Screw
Self tapping screws are fasteners designed to create or cut their own mating threads as they are driven into a predrilled pilot hole. Instead of relying on existing threads in a nut or tapped hole, the screw forms threads in the material, which makes them common in sheet metal, plastics, and some wood and composite applications. Self tapping screws are available in many head styles and drives, and they often have point designs optimized for specific materials.
Self tapping screws still require the correct pilot hole size to work properly. If the hole is too small, driving torque can be excessive and the screw may break or strip out the material. If the hole is too large, the threads may not develop enough engagement and the connection can loosen. Choosing the right self tapping screw involves matching the screw type to the material, selecting the proper length and diameter, and using an appropriate coating for corrosion resistance when used outdoors or in damp environments.