Metal working lathe

Metal is removed from the workpiece using a hardened cutting tool, which is usually fixed to a solid moveable mounting called the "toolpost", which is then moved against the workpiece using handwheels and/or computer controlled motors. The toolpost is operated by leadscrews that can accurately position the tool in a variety of planes. The toolpost may be driven manually or automatically to produce the roughing and finishing cuts required to turn the workpiece to the desired shape and dimensions, or for cutting threads, worm gear,etc. Cutting fluid may also be pumped to the cutting site to provide cooling, lubrication and clearing of swarf. from the workpiece. Some lathes may be operated under control of a computer for mass production (Computer Numerical Control ).Metalworking lathes are commonly provided with a variable ratio gear train to drive the main leadscrew. This enables different pitches of threads to be cut. Some older gear trains are changed manually by using interchangeable gears with various numbers of teeth, while more modern or elaborate lathes have a quick change box to provide commonly used ratios by the operation of a lever.