Turn milling is a hybrid machining technique that combines features from both turning and milling in the same machine, known as a turn-mill. Turn milling centers typically have a chuck and a tail stock to mount and rotate the workpiece, as in a turning machine. In addition to this, they also have specialized tool-holding devices with rotating cutting tools, as in a milling process.
The milling cutter in turn-milling centers is maneuverable in multiple directions, including both parallel and perpendicular to the workpiece axis (see figure below).
This type of dual functionality allows turn milling centers to produce parts with both cylindrical and prismatic features in the same setup. This boosts productivity, accuracy, and saves costs.