Cutting tool geometry

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 20.12.2018 2

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 20.12.2018 3 [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] 20.12.2018 4

5. Single Point Cutting Tool 20.12.2018 5

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 20.12.2018 6

7. Cutting Planes Tool Assumed Working Plane ( Pf ) Side Rake Angle ( α s) Side Relief Angle (SRA) Tool Back Plane ( Pp ) Back Rake Angle ( α b) Wedge Angle End Relief Angle (ERA) Tool Reference Plane (Pr) End Cutting Edge Angle (ECEA) Side Cutting Edge Angle (SCEA) 20.12.2018 7

8. Single Point Cutting Tool 20.12.2018 8

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 . 20.12.2018 9

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 degree is for thread cutting 20.12.2018 10 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 to 35 degrees 20.12.2018 11

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 20.12.2018 12

13. Tool Signature Tool signature describes the tool angles in standardized system (ASA and ORS) 20.12.2018 13 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 20.12.2018 14

15. Twist Drill Used for cutting holes in rigid materials 20.12.2018 15 [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 20.12.2018 16

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 20.12.2018 17

18. Twist Drill 20.12.2018 18 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 20.12.2018 19

20. An Example : Pipe Facing Machine 20.12.2018 20 [10] Multiple Single Point Cutting Tools Workpiece is not turning , Cutting tools are turning

21. An Example : Pipe Facing Machine 20.12.2018 21 Beveling result on the pipe

22. An Example : Pipe Facing Machine 20.12.2018 22 Single Point Cutting Tool

23. An Example: Pipe Facing Machine 20.12.2018 23 https://www.youtube.com/watch?v=9IwQlsVtFh4

24. To Sum Up 20.12.2018 24 [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 Flan k 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] 20.12.2018 25

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] 20.12.2018 26

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] 20.12.2018 27