One of the most important machine tools in metal industry is the lathe. The main function of a lathe is to remove material from a workpiece so as to give it the required shape and size. A suitable classification of lathe machines is difficult due to many variations available in their size, design, methods of drive and applications. The generally used classification of the lathe is as follows:
• Speed Lathe
This is simplest of all types of lathes. It consists of a bed, a headstock, a tailstock, and an adjustable slide for supporting the tool. The tool is mounted on an adjustable slide and is fed into the work by hand control. The lathe is driven at high speed with spindle speeds of about 4000 RPM. The reason of using high speed being use of small depth of cut and hand tools. The speed lathe is principally used for turning wood, patterns, and centering cylindrical parts prior to further work on the engine lathe. The “Speed lathe” has been so named because of the high speed of the head stock spindle. The work can be held between centers on a chuck or attached to a faceplate on the headstock.
• Engine Lathe or Centre Lathe
An engine lathe is a general-purpose lathe machine. It is used to perform a variety of operations. The engine lathe derives its name from the early lathes, which were powered by steam engines. It differs from a speed lathe in that it has additional features for controlling the spindle speed and for supporting and controlling the feed of the fixed cutting tool. Engine lathes are provided with a tailstock to facilitate the holding of the work between centers and permit the use of tool like drills, reamers, tapes etc. Centre lathes are built to handle work up to 1000 mm in diameter and 1000-4000mm in length. Several variations in the design of the headstock are available through which the power can be supplied to the machine.
• Light or medium duty lathes receive their power through a short belt from a motor or