Short Answer:

Cutting tools are instruments used in machining processes to remove unwanted material from a workpiece and give it the desired shape, size, and finish. They work by applying a wedge-shaped edge that shears off material in the form of chips.

These tools are made from hard materials like high-speed steel, carbide, or diamond to withstand high temperatures and forces during cutting. Examples include lathe tools, milling cutters, drills, and reamers. The efficiency and accuracy of machining largely depend on the proper selection and maintenance of cutting tools.

Detailed Explanation :

Cutting Tools

Cutting tools are essential components in machining operations such as turning, milling, drilling, and shaping. Their main purpose is to remove excess material from a workpiece to achieve a specific shape, dimension, or surface finish. A cutting tool performs this task by means of a sharp edge that comes into direct contact with the workpiece under controlled motion and pressure.

A cutting tool must be harder than the material it cuts, maintain its sharpness at high temperatures, and resist wear, deformation, and breakage. The performance of cutting tools directly affects machining accuracy, surface quality, production speed, and tool life.

Functions of Cutting Tools

The main function of a cutting tool is to shear off material in the form of chips. This process converts the raw material into a useful product with the required dimensions and surface quality. Cutting tools help in:

1. Removing material in a controlled manner.
2. Providing accurate shapes and smooth finishes.
3. Increasing productivity by reducing machining time.
4. Maintaining precision and repeatability in manufacturing.

Types of Cutting Tools

Cutting tools are mainly divided into two categories based on the number of cutting edges:

1. Single Point Cutting Tools:
   • These tools have one main cutting edge.
   • They are generally used in operations like turning, shaping, and planning.
   • Example: Lathe tool, shaper tool.
2. Multi Point Cutting Tools:
   • These tools have multiple cutting edges that remove material simultaneously.
   • They are used in high-speed operations like drilling, milling, and grinding.
   • Example: Milling cutter, drill bit, grinding wheel.

Material Used for Cutting Tools

The performance of a cutting tool greatly depends on the material from which it is made. The tool material should possess properties like hardness, toughness, wear resistance, and ability to withstand high temperatures. Common materials include:

1. High-Speed Steel (HSS):
   • Commonly used for general-purpose cutting.
   • Maintains hardness up to 600°C.
2. Carbide:
   • Harder and more wear-resistant than HSS.
   • Used for high-speed machining.
3. Ceramics and Cermets:
   • Offer excellent hardness and temperature resistance.
   • Used for finishing operations.
4. Diamond and Cubic Boron Nitride (CBN):
   • Extremely hard materials.
   • Suitable for cutting very hard or brittle materials.

Requirements of a Good Cutting Tool Material

A good cutting tool material should have the following properties:

• High hardness to cut other materials effectively.
• High wear resistance to increase tool life.
• Toughness to resist shock and vibration.
• Thermal stability to withstand high cutting temperatures.
• Low coefficient of friction for smooth cutting.

Geometry of Cutting Tools

The geometry or shape of a cutting tool plays an important role in its cutting performance. The main elements of tool geometry include:

• Rake Angle: Helps the chip to flow smoothly away from the cutting zone.
• Relief Angle: Prevents the tool from rubbing against the workpiece.
• Cutting Edge Angle: Determines the direction of chip flow.
  Proper tool geometry ensures smooth operation, less tool wear, and better surface finish.

Applications of Cutting Tools

Cutting tools are widely used in almost every manufacturing process.

• In turning operations, single-point tools are used to create cylindrical shapes.
• In milling, multi-point tools are used for producing slots and flat surfaces.
• In drilling, holes are made using drill bits.
• In grinding, fine surface finishes are achieved using abrasive wheels.

Thus, cutting tools are vital for shaping, finishing, and manufacturing metal components used in machines, vehicles, and various equipment.

Maintenance of Cutting Tools

To ensure long tool life and accuracy, proper maintenance is necessary. Cutting edges should be regularly sharpened, lubricated, and cooled during operation. Overheating can reduce tool hardness and cause tool failure. Correct speed, feed, and depth of cut should be maintained during machining to achieve the best performance.

Conclusion:

Cutting tools are the heart of machining operations, responsible for shaping materials with precision and efficiency. The right selection of tool type, material, and geometry ensures high-quality products, reduced production costs, and longer tool life. As technology advances, new tool materials and coatings continue to improve cutting performance and productivity in modern manufacturing industries.