A planer is a type of metal machining tool that uses linear relative movement between the workpiece and a single point cutting tool to cut the workpiece. A planer is similar to a shaper, but larger, and with the workpiece moving, while in a shaper the cutting tool moves. Drills and forming machines are now obsolete, because other machine tools (such as milling, grinding and grinding machines) have mainly eclipsed them as the tools of choice to do such work. However, they have not yet disappeared from the metallurgical world. Drills are used by smaller tool shops and dies within larger production facilities to maintain and repair large stamping dies and plastic injection molds. Additional uses include any other task in which an abnormally large metal block (usually in the range of 4 '× 8' or more) should be square when a (fairly massive) horizontal mill or mill is unavailable, too expensive, or Not practical In a given situation. As usual in the selection of machine tools, an old machine that is in the hand, still works, and has long been paid-has a substantial cost advantage over a newer machine that would have to be purchased. This principle easily explains why "old-fashioned" techniques often have a long period of gradual obsolescence in industrial contexts, rather than a sharp fall in prevalence as seen in the fashion of mass-consumption technology.