Machining

Machining is the term given to a collection of processes used to cut metal into a desired geometry. Machining is used to produce just about every manufactured metal product. Lathes, milling machines, and drill presses are a few of the common power-driven machines employed during the various methods of machining. All the work is performed at a machine shop, and the person performing the operations is known as a machinist. The three main categories in machining are turning, drilling, and milling. However, some operations fall into, "miscellaneous," categories like shaping, planing, broaching, burnishing, grinding, and sawing. Turning involves literally rotating the work piece against the cutting tool to remove the desired material. In turning, the cutting tool always has just a single edge. Lathes are the primary tools used in turning operations. The point of the single-edge tool is inserted just below the surface to chip away the material. During drilling, drill bits, rotating cutters, and cutting edges are lowered or brought into contact with the stationary workpiece in order to make round holes. Drill presses are the usual tool of choice for such procedures, although lathes and mills can also be used on occasion. Finally, milling operations are those in which the cutting tool is rotated to remove material from the workpiece. Milling machines differ from drill presses in that their cutting edges can move sideways as well as in and out. The milling cutting tool has multiple edges, making it exceptionally efficient.