Turning the outer round surface is the basic method of machining the outer round surface in hardware processing, and the equipment used is the lathe. In general machinery factories, lathes account for about 40% of the total number of machine tools. Turning is the main method of roughing and semi-finishing the outer circular surface of all kinds of materials, and it is also the final finishing method of all kinds of materials that are not suitable for grinding.

In the small batch production of single piece, turning the outer round surface is generally carried out on the ordinary lathe. In mass production, multi-tool semi-automatic lathes or automatic lathes are widely used. Large disc parts should be processed on vertical lathes. Large long shaft parts need to be processed on heavy horizontal lathes.

The characteristics of the turning surface are as follows: 

1. The cutting tool is simple, manufacturing, grinding and installation are convenient; 

2, the cutting process is stable, the cutting force fluctuation is small, is conducive to the use of high cutting speed, improve productivity; 

3, the machine versatility is good, can be processed in a clamping outer circle, end face, inner hole, thread and chamfer, etc. The mutual position accuracy of each surface is easy to guarantee; 

4, suitable for non-ferrous metal parts finishing.