Pilot hole

A pilot hole is a small hole drilled into a piece of construction material. Its purpose is a) to guide a larger drill to the appropriate location and ease the job of the larger drill, b) to allow for the insertion of another hole-making tool, such as a knockout punch, that will produce the final-sized hole, or c) to locate, guide, and provide clearance for a self-threading screw in wood or plastic to prevent damaging the material or breaking the screw. A pilot hole is a small hole drilled into a piece of construction material. Its purpose is a) to guide a larger drill to the appropriate location and ease the job of the larger drill, b) to allow for the insertion of another hole-making tool, such as a knockout punch, that will produce the final-sized hole, or c) to locate, guide, and provide clearance for a self-threading screw in wood or plastic to prevent damaging the material or breaking the screw. A pilot hole may be drilled the full extent of the final hole, or may only be a portion of the final depth. The pilot drill may be a standard twist drill, another type of drill bit appropriate for the material, or, when the primary purpose is precisely locating a hole, may be made with a short, stiff center drill.