Lathe is one of the most versatile and widely used machine tools all over the world. It is commonly known as the mother of all other machine tool. The main function of a lathe is to remove metal from a job to give it the required shape and size. The job is securely and rigidly held in the chuck or in between centers on the lathe machine and then turn it against a single point cutting tool which will remove metal from the job in the form of chips. The cutting tool is rigidly held and supported in a tool post and is fed against the revolving work.

In order to perform different machining operations in a lathe,the work piece may be supported and driven by any of the following method

• Held between centers and driven by carriers and catch plate.
• Held on mandrel which is supported between centers and driven by carriers and catch plate.
• Held and driven by chuck with the other end supported on the tailstock center.
• Held and driven by chuck.

OPERATIONS BY HOLDING THE WORKPIECE BETWEEN CENTERS

1. FACING:

 It is the operation of machining the ends of a piece of work to produce a flat surface

2. STRAIGHT TURNING:

 The work is turned straight when it is made to rotate about the lathe axis, and the tool is fed parallel to the lathe axis. The straight turning produces a cylindrical surface by removing excess metal from the work piece.

3. SHOULDER TURNING:

 When work piece having different diameters is turned, the surface forming the step from one diameter to other is called the shoulder, and machining of this part of the work piece is called shoulder turning.

4. CHAMFERING:

 It is the operation of bevelling the extreme end of the work piece.