a lathe-type metalcutting machine tool equipped with a multiposition rotating turret that holds tools for working exterior and interior surfaces by turning, boring, drilling, countersink reaming, reaming, or knurling.

Turret lathes are used for machining parts with complex shapes from bar stock or individual blanks. Screw machines are turret lathes equipped with a feeding and clamping mechanism for bar stock. Turret lathes for matching individual blanks are known as chucking machines; they are equipped with a chuck having a manual or mechanized clamp. Turret lathes may have a vertical, horizontal, or inclined turret; they may be manual, mechanized, or automatic. In manual turret lathes, the bar stock is fed by hand, and the turret is rotated automatically when the saddle returns to the initial position. Mechanized turret lathes usually have mechanized clamping, bar feed, and saddle motion. Automatic turret lathes are equipped with devices for automatically shifting spindle speeds and saddle feed rates during rotation of the turret. In turret lathes with cyclic program control, the cycle and the movements of the working components are automated by electromagnetic clutches, electric motors, and hydraulic cylinders. The machining program is fed from a plug-in installation, and the movements of the working components are controlled by adjustable stops that actuate positional switches.

Tooling is set up away from the lathe in order to increase labor productivity. Stops are also adjusted to the required dimensions away from the lathe on a quick-change, preset drum, which is mounted on the lathe. Turret lathes are used in small-scale and lot production.

The development of the turret lathe led to the creation of semiautomatic turret lathes—principally chucking machines with automation of the operating cycle (except for the loading and unloading of workpieces) and cyclic or numerical control. Semiautomatic turret lathes are used in lot and large-scale production; small-scale production is also carried out in connection with the expanding use of program control.