Lathe Cutting Tools

Lathe Cutting Tools

Lathe cutting tools are used to remove material from a rotating workpiece in a lathe machine. These tools help in shaping, turning, facing, and finishing metal components. Lathe cutting tools are generally made from high speed steel (HSS), carbide, or other hard materials that can withstand high cutting temperatures.

Nomenclature of Cutting Tools

The nomenclature of a cutting tool refers to the different parts and angles that form the tool geometry.

Main Parts of a Single Point Cutting Tool

• Shank: The main body of the tool held in the tool holder.
• Face: The surface over which chips flow.
• Flank: The surface below the cutting edge.
• Cutting Edge: The edge that removes material from the workpiece.
• Nose: The tip of the cutting tool.
• Side Cutting Edge: The edge that performs the main cutting action.
• End Cutting Edge: The edge that prevents rubbing of the tool.

Single Point and Multipoint Cutting Tools

Single Point Cutting Tools

Single point cutting tools have only one cutting edge and are commonly used in lathe machines.

Examples

• Turning tool
• Facing tool
• Thread cutting tool
• Parting tool

Multipoint Cutting Tools

Multipoint cutting tools have multiple cutting edges and are used in machines such as milling machines and drilling machines.

Examples

• Milling cutter
• Drill
• Reamer
• Broach

Tool Selection Based on Requirements

The selection of a cutting tool depends on several factors such as the type of material, required surface finish, cutting speed, and machining operation.

• Use HSS tools for general machining work.
• Use carbide tools for high-speed machining.
• Select proper tool geometry depending on the workpiece material.
• Choose suitable tool material for durability and performance.

Necessity of Correct Grinding

Proper grinding of cutting tools is essential to maintain correct tool angles and sharp cutting edges. Incorrect grinding may lead to poor surface finish, excessive tool wear, and vibration during machining.

Advantages of Correct Grinding

• Improves cutting efficiency.
• Reduces tool wear.
• Produces better surface finish.
• Ensures proper chip removal.

Types of Lathe Cutting Tools

Solid Tools

Solid tools are made entirely from a single material such as high speed steel.

Tipped Tools

Tipped tools have a small cutting tip made from hard material such as carbide, brazed onto the tool shank.

Throw Away (Indexable) Tools

Throw away tools use replaceable cutting inserts. When the insert becomes worn, it can be replaced without replacing the entire tool.

Cutting Speed and Feed

Cutting speed is the speed at which the cutting edge moves relative to the workpiece. Feed is the distance the cutting tool advances during one revolution of the workpiece.

Carbide tools can operate at higher speeds compared to HSS tools because they have higher heat resistance and hardness.

Coolants and Lubricants

Coolants and lubricants are used during machining operations to reduce heat, friction, and tool wear.

Functions

• Cooling the cutting tool and workpiece.
• Reducing friction during cutting.
• Improving surface finish.
• Increasing tool life.

Common Types

• Water-based coolants
• Soluble oils
• Straight cutting oils
• Synthetic coolants

Conclusion

Lathe cutting tools are essential for machining operations. Understanding tool nomenclature, proper tool selection, grinding techniques, cutting speeds, feeds, and the use of coolants ensures efficient machining and longer tool life in mechanical workshops.