The turning machines are, of course, every kinds of lathes. Lathes used in manufacturing can be classified as engine, turret, automatics, and numerical control etc.
1-Centre Lathe:
The term Centre Lathe is derived from the fact that in its operation the lathe holds a piece of material between two rigid supports called centres, or by some other device such as a chuck or faceplate which revolves about the centre line of the lathe.
The lathe shown above is a typical example. This machine is usually used in a jobbing (one off) situation or for small batch work where it would be too expensive to specially 'tool up' for just a few items.
The lathe on which you will work is a machine used to cut metal. The spindle carrying the work is rotated whilst a cutting tool, which is supported in a tool post, is made to travel in a certain direction depending on the form of surface required. If the tool moves parallel to the axis of the rotation of the work a cylindrical surface is produced as in Fig 2 (a) , whilst if it moves at right angles to this axis it produces a flat surface as in Fig 2 (b).








The lathe can also be used for the purposes shown in Fig 2c, 2d, 2e and 2f.

2-Turret Lathes:
In a turret lathe, a longitudinally feedable, hexagon turret replaces the tailstock. The turret, on which six tools can be mounted, can be rotated about a vertical axis to bring each tool into operating position, and the entire unit can be moved longitudinally, either annually or by power, to provide feed for the tools. When the turret assembly is backed away from the spindle by means of a capstan wheel, the turret indexes automatically at the end of its movement thus bringing each of the six tools into operating position. The square turret on the cross slide can be rotated manually about a vertical axis to bring each of the four tools into operating position. On most machines, the turret can be moved transversely, either manually or by power, by means of the cross slide, and longitudinally through power or manual operation of the carriage. In most cased, a fixed tool holder also is added to the back end of the cross slide; this often carries a parting tool.

Through these basic features of a turret lathe, a number of tools can be set on the machine and then quickly be brought successively into working position so that a complete part can be machined without the necessity for further adjusting, changing tools, or making measurements.

Single-Spindle Automatic Screw Machines:
There are two common types of single-spindle screw machines, One, an American development and commonly called the turret type (Brown & Sharp), is shown in the following figure. The other is of Swiss origin and is referred to as the swiss type. The Brown & Sharp screw machine is essentially a small automatic turret lathe, designed for bar stock, with the main turret mounted on the cross slide. All motions of the turret, cross slide, spindle, chuck, and stock-feed mechanism are controlled by cams. The turret cam is essentially a program that defines the movement of the turret during a cycle. These machines usually are equipped with an automatic rod feeding magazine that feeds a new length of bar stock into the collect as soon as one rod is completely used.
3-CNC Machines:

Nowadays, more and more Computer Numerical Controlled (CNC) machines are being used in every kinds of manufacturing processes. In a CNC machine, functions like program storage, tool offset and tool compensation, program-editing capability, various degree of computation, and the ability to send and receive data from a variety of sources, including remote locations can be easily realized through on board computer. The computer can store multiple-part programs, recalling them as needed for different parts. A CNC turret lathe in Michigan Technological University is shown in the following picture.