What is Turning in Lathe Machine – A Detailed Guide

What is Turning in Lathe Machine, Turning is one of the most fundamental operations performed on a lathe machine, which is widely used in mechanical engineering workshops and manufacturing industries. It is a metal cutting process in which a workpiece rotates, and a cutting tool removes material from its surface to create a cylindrical shape. Turning is crucial in making shafts, rods, bushings, and other cylindrical components.

1. What is Turning in lathe machine?

Turning is a machining process in which a single-point cutting tool removes material from the outer diameter (OD) or inner diameter (ID) of a rotating workpiece.

• The workpiece is held in the lathe chuck and rotated at a desired speed.
• The cutting tool moves linearly along the workpiece, producing a smooth cylindrical shape.
• Turning can also be performed internally (boring) or on tapered surfaces.

Key Definition:

Turning is the process of machining a cylindrical surface by rotating the workpiece against a stationary cutting tool.

2. Lathe Machine Components for Turning

To understand turning, it’s important to know the main parts of a lathe machine:

3. Types of Turning Operations

Turning operations can be categorized based on the type of surface produced and tool movement:

1. Straight Turning
   • The tool moves parallel to the axis of rotation.
   • Produces a uniform cylindrical surface.
2. Taper Turning
   • Produces a conical shape.
   • Can be achieved by setting the tool at an angle or using the compound rest.
3. Facing
   • The tool moves perpendicular to the axis of rotation.
   • Used to create a flat surface at the end of the workpiece.
4. Parting / Cut-off
   • Removes a finished piece from the remaining stock.
5. Chamfering
   • Removes sharp edges at the end of the workpiece for safety and aesthetics.
6. Threading
   • Produces screw threads on the workpiece using a single-point tool.

4. Tools Used in Turning

• Single-Point Cutting Tool: Standard tool for turning operations.
• Carbide or HSS Tools: Depending on material and cutting speed.
• Tool Geometry:
  • Rake angle – controls cutting efficiency.
  • Clearance angle – prevents tool rubbing.
  • Nose radius – affects surface finish.

5. Turning Parameters

To perform turning efficiently, the following parameters must be controlled:

1. Cutting Speed (V) – Speed of the workpiece surface in m/min or ft/min.
2. Feed (f) – Distance the tool advances along the workpiece per revolution (mm/rev).
3. Depth of Cut (d) – Thickness of the material layer removed in one pass (mm).
4. Spindle Speed (N) – Revolutions per minute (RPM) of the workpiece.

Formula for Spindle Speed: N=1000×Vπ×DN = \frac{1000 \times V}{\pi \times D} N=π×D1000×V​

Where:

• VVV = Cutting speed (m/min)
• DDD = Workpiece diameter (mm)
• NNN = Spindle speed (RPM)

6. Advantages of Turning

• Produces accurate cylindrical shapes.
• Can create internal and external surfaces.
• Suitable for small to large production runs.
• Works on different materials – metals, plastics, and wood.

7. Applications of Turning

Turning is widely used in industries like:

• Automobile Industry – shafts, axles, piston rods.
• Manufacturing – gears, rollers, bushings.
• Tool Room – precision components for machines.
• Engineering Workshops – prototypes, repairs, and small-scale production.

8. Safety Precautions

• Always wear safety goggles to protect eyes from flying chips.
• Keep hands and clothing away from rotating workpieces.
• Check tool alignment before starting the lathe.
• Use proper coolant or lubricant to prevent overheating.

Conclusion

you must know all types of lathe machine to perform a turning operation and Turning on a lathe machine is an essential and versatile machining process that allows precise shaping of cylindrical components. By controlling cutting speed, feed, and depth of cut, high-quality surfaces and accurate dimensions can be achieved. Mastering turning is fundamental for anyone in mechanical engineering or manufacturing industries.