Single Point Cutting Tool Geometry and Nomenclature
A cutting tool in Mechanical Engineering is a tool used to cut or remove any other material by application of force. In our daily life, we use knives and scissors are also examples of cutting tools. Where Single Point Cutting Tool removes chip or cuts the material from work-piece by means of single-point or edge attached with shank. Cutting tools are most widely used in industries for creating the required shape of the product by facing, turning, chamfering, shaping, drilling, boring and many other operations. Lathe machine and shaper machines having single-point cutting tools in most of the operations. In industries most widely examples of single-point cutting tools are turning tools, boring tools, shaping tools, planning and slotting tools.
The objective of this post is to know about tool angles like clearance angle, rake angle, relief angle and various other geometry of cutting tools. Let’s, we will discuss single point cutting tool geometry, various angles, nomenclature, signature and material.
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Single Point Cutting Tool Geometry and Nomenclature :
By means of cutting tool, Nomenclature is the systematic naming of various parts and angles of cutting – tool. The above image shows the complete nomenclature of a single-point cutting tool. These are Shank, base, face, flank, heel, nose, back rake angle, side rake angle, side clearance, wide cutting edge, end cutting edge, and lip angle.
- Shank – Shank is the main body of the cutting tool which is grabbed by the tool holder on the machine. It is a larger part of the tool in aspects of volume.
- Face – Face is the surface of the tool where chips slide towards to up and outward side, during the machining process.
- Base – The bottom surface of the tool is known as the base, on which the tool stands.
- Nose or Cutting Point – A point where side and End cutting edges are meets in front of the tool. It is also known as the Cutting Point of the tool. And Nose radius is the radius of the nose that helps to achieve better surface finishing as well as increases tool life.
- Heel – A line of intersection of flank and base surfaces is known as Heel of a single-point cutting tool.
- Flank – Cutting tools having two flank surfaces, i.e; Major Flank and Minor Flank. Major flank is a vertical surface adjacent to the side cutting edge. And Minor flank is a vertical surface adjacent to the end cutting edge. But, both surfaces are not actually vertical, they slightly inclined towards the base. Cutting Face is another name of Flank.
- Cutting Edge – Edges which used to remove material during the machining process called as cutting edge. Face and cutting surfaces makes Cutting Edges. Single point cutting tools having two cutting edges as side cutting edge and end cutting edge.
#. Side Cutting Edge – Edge or line made by face and minor flank or minor cutting surface.
#. End Cutting Edge – As like side cutting edge, end cutting edge made by face and major flank or major cutting surface.
Single Point Cutting Tool Angles :
- Rake Angle –
#. Back Rake Angle – The back rake angle of a single-point cutting tool, is the angle between the face of the tool and the horizontal line which is parallel with the baseline of the tool. A back rake angle is useful in removing the chip away from the work-piece during the machining process and also provides easiness in the machining process. If the slope of the face is downward toward the nose, known as Negative Back Rake Angle. That makes blunt cutting edge of the tool. But increases the strength of the edge. It will increases the required power and cutting forces, and also increases the friction between tool and work-piece. But may helps to improve the surface finishing of the product. And If the slope faces is upward toward, known as Positive Back Rake Angle. Generally, a positive rake angle makes tools more sharper. So, this reduces the required power and cutting forces during machining. But also reduces tool strength. And it can help to avoid the formation of a built-up edge.
If the slope is parallel with baseline, known as Neutral or Zero Rake Angle. It is easy to manufacture and resharpen. It requires lesser power requirement and cutting force than a negative rake angle.
#. Side Rake Angle – Side Rake Angle is an angle face and perpendicular line to the shank. As same as the side rake angle, back rake angle it is also helpful in removing chip during the machining process. It provides clearance between side flank and work-piece to prevent rubbing.
- Relief Angle – The meaning of relief is clearance. So, the relief angle having another name is Clearance Angle.
#. End Relief Angle – End relief angle is defined as the angle between minor flank or minor cutting face and perpendicular line to the base that makes the right angle with a flank. Therefore, it avoids rubbing with the workpiece against the tool in a lateral direction.
#. Side Relief Angle – Side relief angle is defined as the angle between the Major flank or major cutting face and perpendicular plane to the base that makes a right angle with the side. It also avoids rubbing with the workpiece against the same as End relief angle but in a longitudinal direction.
- Cutting Edge Angle –
Side Cutting Edge angle is defined as an angle between side cutting edge and parallel line to the shank. In another name also called Lead Angle. And End Cutting angle is the angle between the end cutting edge and perpendicular line to the shank.
The meaning of relief is clearance. So, the relief angle having another name is Clearance Angle.
#. End Relief Angle - End relief angle is defined as the angle between minor flank or minor cutting face and perpendicular line to the base that makes the right angle with a flank. Therefore, it avoids rubbing with the workpiece against the tool in a lateral direction.
#. Side Relief Angle - Side relief angle is defined as the angle between the Major flank or major cutting face and perpendicular plane to the base that makes a right angle with the side. It also avoids rubbing with the workpiece against the same as End relief angle but in a longitudinal direction
In industries most widely examples of single-point cutting tools are turning tool, boring tool, shaping tool, planning and slotting tool.