In woodworking/metalworking, a lathe is a machine tool which rapidly spins a block of material along a horizontal axis so that when abrasive or cutting tools are applied to the block, it can be shaped to produce an object which has symmetry about the rotation axis. Examples of objects that can be produced on a lathe include candlesticks, table legs, and baseball bats.
The material is held in place by two prongs, at least one of which can be moved horizontally to accommodate varying material lengths. An adjustable horizontal metal rail between the material and the operator accommodates the positioning of shaping tools. With wood, it is common practice to press and slide sandpaper against the still-spinning object after shaping.
In a metalworking lathe, metal is removed from the workpiece using a hardened cutting tool, which is usually fixed to a solid moveable mounting called the toolpost. This is in contrast to a woodworking lathe where most tools are hand held. The toolpost is manually operated by screwthreads to position the tool in a variety of planes. The toolpost may also be automatically driven to produce automatic finishing of a piece, or for cutting threads, gears, 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 of parts (see CNC).
In 3D computer graphics, a lathed object is a 3D model whose vertex geometry is produced by rotating the points of a spline or other point set around a fixed axis. The lathing may be partial; the amount of rotation is not necessarily a full 360 degrees. The point set providing the intial source data can be thought of as a cross section through the object.