Drill

Drill refers to a tool that creates holes by rotation and impact. The most familiar drill is a hand-held twist drill used in wood or metal, but drills include manual braces, electric and cordless drills, hammer drills, and mechanical drill presses. Common drill bits include twist bits, brad-point bits for clean wood holes, spade bits for large-diameter wood holes, masonry bits for concrete, and Forstner bits for flat-bottomed holes. A drill press provides fixed speed, precise alignment, and depth control.

In use, drills bore holes for fasteners, to pass wires, or to create clean pilot holes. They come with various chuck types and speeds. Safety considerations include wearing eye protection, securing the workpiece, and using the correct bit for the material to reduce breakage and kickback.

Other meanings of drill include organizational and training contexts. Military and police organizations use drill to describe planned training routines and marching movements designed to teach discipline and coordination; ceremonial parades often feature drill teams. In dentistry, a dental drill is a high-speed handpiece used to remove decay and shape tooth preparation, typically powered by a turbine or electric motor. The term can also refer to repetitive practice used to sharpen skills or rehearse procedures, such as a fire drill or emergency drill.

Drilling refers to the process of creating a bore in earth or rock for extraction or exploration. This includes water wells, mineral or oil and gas exploration, and geothermal projects. Drilling operations rely on rigs, drill strings, casings, and drilling mud to maintain pressure, transport cuttings, and stabilize the bore, with offshore and onshore setups differing in equipment and safety considerations.