Machine tool

Machine tool, nonportable, power-driven tool used industrially for working metal components to tolerances far finer than those obtainable manually. The fundamental processes used are cutting and grinding, individual machines being designed for boring, broaching, drilling, milling, planing, and sawing. Essentially a machine tool consists of a jig to hold both the cutting tool and the workpiece and a mechanism to allow these to be moved relative to each other in a controlled fashion. A typical example is the lathe. Auxiliary functions facilitate the cooling and lubrication of the tool and workpiece while work is in progress using a cutting fluid. The rate at which any piece can be worked depends on the material being worked and the composition of the cutting point. High-speed steel, tungsten carbide, and corundum are favored materials for cutting edges. Modern industry would be inconceivable without machine tools. It was only when these began to be developed in the late 18th century that it became possible to manufacture interchangeable parts and thus initiate mass production.