The metalworking process of 'turning' defines the task that is typically performed on a lathe. Over time, as lathes have become more sophisticated, a few of these specialized machines have been assigned distinct names. The term 'Turning centers' is often given to equipment with especially advanced functionality regarding supplementary spindles and/or revolving tools for milling as well as drilling. A different name, 'turn-mill machine,' identifies machines which might be considered equally as capable at drilling or milling components as they are at the task of turning.

During the process of turning, in contrast to milling and drilling, the actual workpiece spins rather than the cutting tool. The fixed cutting tool travels along the length or face of the revolving part. Two common devices for securing a workpiece in a lathe are the chuck and collet.

The turning machine can also incorporate spindles for the cutting tools to undertake non-turning procedures including milling and drilling. In this situation, the machine halts the workpiece from rotating to be able to carry out these types of procedures during the very same machining process as the turning job. In actual fact, for many components, the drilling and milling functionality can be utilized so effectively that a non-rounded, non-turned, piece may effectively be created on this sort of equipment. Lathes and turning centers, together with turn/mill machines, may have vertical or horizontal spindles. Horizontal spindles tend to be more typical. Where the machine incorporates an up and down spindle device, the spindle can be beneath or on top of the machine. When the work surface sits on a table powered by the spindle, this particular device is usually known as a vertical turret lathe, (VTL.) When the job is secured from above by way of the vertical spindle, this kind of turning machine is normally referred to as an inverted vertical lathe.