Cutting tool geometries for single and multi point cutting tools with their cutting planes and important angles and their values.

1. ME 557: Metal Cutting Principles
Cutting Tool Geometry
Prepared By:
Ali Kemal Giregiz - 21400215
Engincan Buharalı - 21402205

2. Table Of Contents
• Types of Tools
• Single Point Cutting Tool
• Cutting Planes
• Tool Assumed Working Plane (Pf)
• Tool Back Plane (Pp)
• Tool Reference Plane (Pr)
• Tool Signature
• Multi Point Cutting Tools
• Twist Drill
• Miller Cutter
• Summary
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3. Types Of Tools
• Single Point Cutting Tools
• One cutting tip
• e.g. Lathe machine tools, shaping tools
• Multi Point Cutting Tools
• More than one cutting tip
• e.g. Drill (2 cutting tips), milling cutter
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[1] [2]

4. Single Point Cutting Tool
• Cutting operation is done with having a wedge shape
• Such shape is obtained by the intersection of
• Rake Surface (face) and,
• Flank Surface
• This intersection gives rise to a sharp edge called
cutting edge
• A cutting tool should have at least one flank and rake
surface [3]
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5. Single Point Cutting Tool
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6. Single Point Cutting Tool
• Principle (Main) Cutting Edge
• Mainly responsible for cutting action during machining
• Also called side cutting edge
• Auxiliary (Minor) Cutting Edge
• Sometimes occurs in cutting action
• Used for surface smoothening, etc.
• Also called end cutting edge
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7. Cutting Planes
• Tool Assumed Working Plane (Pf)
• Side Rake Angle (αs)
• Side Relief Angle (SRA)
• Tool Back Plane (Pp)
• Back Rake Angle (αb)
• Wedge Angle
• End Relief Angle (ERA)
• Tool Reference Plane (Pr)
• End Cutting Edge Angle (ECEA)
• Side Cutting Edge Angle (SCEA)
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8. Single Point Cutting Tool
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9. Tool Assumed Working Plane (Pf)
• As side rake angle increases [4]
• Strength of tool increases
• Forces are decreased (small
amount)
• Power required for machining is
decreased (small amount)
• Tool life increases
• Generally, side rake angle is
between 5 to 15 degrees
• Relief angle is useful to avoid
rubbing (friction) between tool
and workpiece.
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10. Tool Back Plane (Pp)
• As back rake angle increases [4]
• Strength of tool increases
• Forces on tool decreases
• Power required for machining is
decreased
• Tool life increases
• Maximum rake angle can be
+45 to -10 degrees
• 0 degree is for thread cutting
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• As relief angle increases [4]
• Strength of tool decreases
• Forces are slightly decreases
• Tool life slightly increases

11. Tool Reference Plane (Pr)
• Cutting edge angle mainly
influence the surface finish of
component
• As side cutting edge angle
increases (or decreasing end
cutting edge angle) [4]
• Surface finish increases
• Nose size increases
• Side cutting edge angle varies
from 0 to 35 degrees
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12. Tool Reference Plane (Pf)
• Also, up to certain values of increasing side cutting
edge angle results [5]
• Increase in tool life
• But friction increases due to more contact with workpiece
• Width of chip increases which results more tool vibration
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13. Tool Signature
• Tool signature describes the tool angles in
standardized system (ASA and ORS)
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TOOL SIGNATURE (ANGLE VALUES)
American Standard Association
(ASA)
Orthogonal Rake System (ORS)
Back Rake Angle 0° 5°
Side (Normal) Rake Angle 10° 10°
End Relief Angle 6° 6°
Side Relief Angle 6° 6°
End Cutting Edge Angle 10° 5°
Side Cutting Edge Angle 12°
Nose Radius 1 mm 1 mm

14. Multi Point Cutting Tools
• The number of cutting edges varies from 2 (drill) to 4
(milling cutter) to hundreds (grinding wheel)
• Provides high material removal rate without failure [6]
• Higher feed rate
• Higher depth of cut
• Chip load is low (as entire load is uniformly distrubuted)
• However, usage of multi point cutting tools can result
[6]
• Fluctuation in cutting force
• Impact loading on each teeth
• Higher vibration effects
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15. Twist Drill
• Used for cutting holes in rigid materials
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[7]

16. Twist Drill [7] [8]
• Flutes: Helical or straight grooves cut to provide cutting edge. They permit
removal of chips and allow cutting fluid to reach cutting lips.
• Helix (Rake) Angle: Improves the chip cutting ability if increased as positive
rake angle
• Lip Relief Angle: On larger diameters or harder materials, this angle is
decreased to as low as 8 degrees, on smaller diameters or softer materials
angle can be increased up to 24 degrees
• Point Angle: Lower angle produces wider chips. Higher angle is recommended
for hard material whereas lower angle is for softer materials
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17. Twist Drill [7] [8]
• Chisel Edge: It does not cut, it
penetrates displacing the workpiece.
It consumes 60% to 70% of the thrust
force required
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18. Twist Drill
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THE BEST TOOL GEOMETRY ANGLES ACCORDING TO MATERIALS
W.P Material Point Angle Helix Angle Lip Relief Angle
Aliminum 90 To 135 32 to 48 12 To 26
Brass 90 to 118 0 to 20 12 to 26
Cast Iron 90 to 118 24 to 32 7 to 20
Mild Steel 118 to 135 24 to 32 7 to 24
Stainless Steel 118 to 135 24 to 32 7 to 24
Plastics 60 to 90 0 to 20 12 to 26

19. Miller Cutter [9]
• Relief Angle: It is to avioid the
interference between the land of
the tooth and the work surface.
• Radial Rake Angle: It is provided
free cutting by allowing chips to flow
smoothly on the face of the cutter
• Lip Angle: It is between the face of
teeth and the land of the teeth
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20. An Example: Pipe Facing Machine
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[10]
Multiple Single Point Cutting
Tools
Workpiece is not turning,
Cutting tools are turning

21. An Example: Pipe Facing Machine
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• Beveling result on the
pipe

22. An Example: Pipe Facing Machine
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Single Point Cutting Tool

23. An Example: Pipe Facing Machine
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• https://www.youtube.com/watch?v=9IwQlsVtFh4

24. To Sum Up
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[11]

25. References
[1] "Lathe Machine Cutting Tool Holder", [Online]. Available:
https://www.ecplaza.net/products/lathe-machine-cutting-tool-
holder_2199675 [Accessed on December 18, 2018]
[2] "Precision Twist Drill", [Online]. Available:
https://midiowatools.com/catalogue/product/904155 [Accessed on
December 18, 2018]
[3] "What is Flank Surface in Cutting Tool? Principal & Auxiliary Flank
Surfaces", [Online]. Available:
http://www.minaprem.com/machining/cutter/geometry/what-is-flank-
surface-in-cutting-tool-principal-auxiliary-flank-surfaces/ [Accessed on
December 18, 2018]
[4] "Design of Single Point Cutting Tool", [Online]. Available:
https://www.slideshare.net/sonusng/design-of-single-point-cutting-tool
[Accessed on December 18, 2018]
[5] "What is the principle cutting edge angle in single point cutting tool?",
[Online]. Available:
https://www.quora.com/What-is-the-principle-cutting-edge-angle-in-single-
point-cutting-tool [Accessed on December 18, 2018]
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26. References
[6] "Concepts of Single Point, Double Point and Multi-Point Cutting Tool",
[Online]. Available:
http://www.minaprem.com/machining/cutter/introduction/concepts-of-
single-point-double-point-and-multi-point-cutting-tool/ [Accessed on
December 18, 2018]
[7] "Twist Drill Nomenclature", [Online]. Available:
https://www.mecholic.com/2017/05/twist-drill-nomenclature-parts.html
[Accessed on December 18, 2018]
[8] "Drill Nomenclature and Geometry", [Online]. Available:
http://neme-s.org/2005%20May%20Meeting/drills.pdf [Accessed on
December 18, 2018]
[9] "Elements of Plain Milling Cutter", [Online]. Available:
https://www.mecholic.com/2018/04/elements-of-plain-milling-cutter.html
[Accessed on December 18, 2018]
[10] "Pipe Facing Machine ", [Online]. Available:
http://www.crc-evans.com/equipment/specialized-equipment/End-Prep-
Equipment/pipe-facing-machine-pfm [Accessed on December 18, 2018]
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27. References
[11] "Concepts of Single Point, Double Point and Multi-Point Cutting Tool,
[Online]. Available:
http://www.minaprem.com/machining/cutter/introduction/concepts-
of-single-point-double-point-and-multi-point-cutting-tool/ [Accessed on
December 18, 2018]
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