What is single point cutting tool?

Short Answer:

A single point cutting tool is a type of cutting tool that has only one main cutting edge used to remove material from a workpiece. It is commonly used in operations like turning, shaping, and planning. The single sharp edge cuts the material by shearing it in the form of chips.

These tools are generally made from high-speed steel, carbide, or other hard materials to resist wear and withstand high temperatures. Single point cutting tools are mainly used on lathes and shaping machines for producing cylindrical, flat, or conical surfaces with good accuracy.

Detailed Explanation :

Single Point Cutting Tool

A single point cutting tool is one of the simplest and most widely used tools in the field of machining. It has only one main cutting edge that comes into contact with the workpiece during the cutting process. This tool is primarily used for removing material in operations such as turning on a lathe, shaping on a shaper, and planning on a planer.

The single point cutting tool works on the basic principle of metal cutting, where the sharp edge of the tool shears off material in the form of chips. The cutting edge is positioned at a suitable angle to allow smooth chip flow and to reduce cutting resistance. Because of its simple design, this tool is easy to manufacture, sharpen, and maintain.

Parts of a Single Point Cutting Tool

A single point cutting tool has several important parts, each designed to perform a specific function during machining. These parts are:

  1. Shank:
    The shank is the main body of the tool which is held in the tool post or holder. It provides support and stability during cutting.
  2. Face:
    The face is the surface of the tool over which the chips slide after being removed from the workpiece.
  3. Flank:
    The flank is the surface below and adjacent to the cutting edge. It prevents rubbing of the tool against the work surface.
  4. Cutting Edge:
    The cutting edge is the main part of the tool that actually removes material from the workpiece.
  5. Nose or Point:
    The nose is the part between the side cutting edge and the end cutting edge. It helps in improving surface finish and tool life.

Angles of a Single Point Cutting Tool

The geometry of a single point cutting tool is defined by several angles which help in efficient cutting. These angles are:

  1. Rake Angle:
    This angle allows smooth chip flow over the tool surface. It affects cutting force, temperature, and chip formation.
  2. Relief or Clearance Angle:
    This angle prevents the tool from rubbing against the workpiece. It helps reduce friction and tool wear.
  3. Side Cutting Edge Angle:
    This angle determines the direction of chip flow and helps distribute cutting forces.
  4. End Cutting Edge Angle:
    It helps in preventing interference between the tool and the work surface.
  5. Nose Radius:
    A small rounded nose improves surface finish and reduces tool wear.

Proper selection of these angles is important for smooth operation, better finish, and longer tool life.

Materials Used for Single Point Cutting Tools

Single point cutting tools must be made from materials that can retain hardness at high temperatures and resist wear. Common materials include:

  1. High-Speed Steel (HSS):
    • Used for general-purpose cutting.
    • Can withstand temperatures up to 600°C.
  2. Carbide:
    • Harder and more wear-resistant than HSS.
    • Suitable for high-speed operations.
  3. Ceramic and Cermet:
    • Provide very high hardness and temperature resistance.
    • Used for finishing and continuous cutting.
  4. Diamond and Cubic Boron Nitride (CBN):
    • Used for cutting hard and brittle materials.
    • Offer excellent wear resistance.

Working Principle of a Single Point Cutting Tool

When the tool moves relative to the workpiece, its single sharp cutting edge penetrates the surface of the material. The cutting edge shears off a thin layer in the form of chips. The rake face of the tool guides the chip away from the cutting zone. The tool must be set at proper angles to ensure smooth cutting and to minimize tool wear.

The cutting action involves three main forces — cutting force, feed force, and radial force. These forces influence tool life, surface finish, and machining power consumption.

Applications of Single Point Cutting Tools

Single point cutting tools are widely used in:

  • Turning operations on lathe machines to produce cylindrical or conical surfaces.
  • Shaping operations for producing flat or contoured surfaces.
  • Planning operations for machining large and flat surfaces.

Because of their simplicity, these tools are suitable for both roughing and finishing operations in various machining tasks.

Advantages of Single Point Cutting Tools

  • Simple in design and easy to manufacture.
  • Cost-effective and easy to sharpen.
  • Suitable for different types of machining operations.
  • Provide good control over material removal and surface finish.

Limitations of Single Point Cutting Tools

  • Cutting speed is lower compared to multi-point tools.
  • Higher tool wear due to single cutting edge.
  • Not suitable for very high production rates.

Despite these limitations, single point cutting tools remain highly useful due to their simplicity, versatility, and precision in machining.

Conclusion:

A single point cutting tool is a fundamental tool in machining operations used to remove material with one cutting edge. It plays a major role in shaping, turning, and planning processes. The tool’s geometry, material, and cutting angles determine its efficiency and performance. Due to its simple design and wide range of applications, the single point cutting tool continues to be an essential part of mechanical manufacturing.