1. K.J.Institute of Technology, Savli
Guided by:- Sandeep Dave sir
Made by :
Gaekwad Jahnvi S ( )
Gandhi Jaimil H ( )
Tiwary Nishant S ( ) 1

2. Cutting tool geometry
&
Tool signature

3. Machining Process
Cast, formed and shaped products may need further machining operations to give them the desired final shape, after removal of extra material in the form of chips.
Machining processes remove material from a work piece by
CUTTING ( As in case of machine tools like lathe, shaper etc)
ABRASIVE ( As in case of a grinding wheel)
NON TRADITIONAL ( Processes such as EDM, ECM Etc.)

4. Metal Cutting Processes

5. Turning High proportion of work machined in shop turned on lathe
Turning tool set to given depth of cut, fed parallel to axis of work (reduces diameter of work)
Chip forms and slides along cutting tool's upper surface created by side rake

6. Planing or Shaping Workpiece moved back and forth under cutting tool
Fed sideways a set amount at end of each table reversal

7. Plain Milling
Multi-tooth tool having several equally spaced cutting edges around periphery
Each tooth considered single-point cutting tool (must have proper rake and clearance angles)
Workpiece held in vise or fastened to table
Fed into horizontal revolving cutter
Each tooth makes successive cuts
Produces smooth, flat, or profiled surface depending on shape of cutter

8. Inserted Blade Face Mill
Consists of body that holds several equally spaced inserts
Cutting action occurs at lower corner of insert
Corners chamfered to give strength

9. End Milling
Multi-fluted cutters held vertically in vertical milling machine spindle or attachment
Used primarily for cutting slots or grooves
Workpiece held in vise and fed into revolving cutter
End milling
Cutting done by periphery of teeth

10. Drilling Multi-edge cutting tool that cuts on the point
Drill's cutting edges (lips) provided with lip clearance to permit point to penetrate work piece as drill revolves

11. What is a Cutting Tool
A cutting tool is any tool that is used to remove metal from the work piece by means of shear deformation.
It is one of most important components in machining process
It must be made of a material harder than the material which is to be cut, and the tool must be able to withstand the heat generated in the metal cutting process.
Two basic types
Single point
Multiple point

12. Single Point Cutting Tool

13. Multi Point Cutting Tool

14. Cutting-Tool Materials
Cutting tool bits generally made
High-speed steel
Cast alloys
Cemented carbides
Ceramics
Cermets
Cubic Boron Nitride
Polycrystalline Diamond

15. Cutting Tool Properties
Hardness
Cutting tool material must be 1 1/2 times harder than the material it is being used to machine.
Capable of maintaining a red hardness during machining operation
Red hardness: ability of cutting tool to maintain sharp cutting edge at elevated temp.
It is also sometimes referred to as hot hardness or hot strength

16. Cutting Tool Properties
Wear Resistance
Able to maintain sharpened edge throughout the cutting operation
Same as abrasive resistance
Shock Resistance
Able to take the cutting loads and forces
Shape and Configuration
Must be available for use in different sizes and shapes.

17. High-Speed Steel
May contain combinations of tungsten, chromium, vanadium, molybdenum, cobalt
Can take heavy cuts, withstand shock and maintain sharp cutting edge under red heat
Generally two types (general purpose)
Molybdenum-base (Group M)
Tungsten-base (Group T)
Cobalt added if more red hardness desired

18. Cast Alloy
Usually contain 25% to 35% chromium, 4% to 25% tungsten and 1% to 3% carbon
Remainder cobalt
Qualities
High hardness
High resistance to wear
Excellent red-hardness
Operate 2 ½ times speed of high-speed steel
Weaker and more brittle than high-speed steel

19. Carbide Cutting Tools
First used in Germany during WW II as substitute for diamonds
Various types of cemented (sintered) carbides developed to suit different materials and machining operations
Good wear resistance
Operate at speeds ranging 150 to 1200 sf/min
Can machine metals at speeds that cause cutting edge to become red hot without loosing harness

20. Single Point Cutting Tool

21. Single Point Cutting Tool

22. Know the Single Point Cutting Tool
Shank: Main body of tool, it is part of
tool which is gripped in tool holder
Face: Top surface of tool b/w shank
and point of tool. Chips flow along this
surface
Flank: Portion tool which faces the work. It is surface adjacent to & below the cutting edge when tool lies in a horizontal position.
Point: Wedge shaped portion where face & flank of tool meet.
Base: Bearing surface of tool on which it is held in a tool holder.
Nose radius: Cutting tip, which carries a sharp cutting point. Nose provided with radius to enable greater strength, increase tool life & surface life.
Typical Value : 0.4 mm – 1.6 mm

23. SPC Tool Geometry SIDE RELIEF SIDE CLEARANCE AA Tool Geometry
The geometry of cutting tools refers to the various angles and clearances machined or ground on the tool faces. Although the terms and definitions relating to single-point cutting tools vary greatly, those adopted by the American Society of Mechanical Engineers (ASME) and currently in general use are illustrated in Fig. 31-6.
SIDE RELIEF
SIDE CLEARANCE

24. Nomenclature of Single Point Lathe Tool
The most significant terms in the geometry of a cutting tool angles are:
Relief or clearance angle
Side relief
End relief
Rake angle
Back Rake angle
Side Rake angle
Cutting edge angle
Side Cutting edge angle
End Cutting edge angl
Nose Radius

25. Cutting-Tool Terms Relief or Clearance angle:
Ground on the end and side faces of a tool to prevent it from rubbing on the work piece.
To enable only the cutting edge to touch the work piece.
Side Relief angle:
Angle ground directly below the cutting edge on the flank of the tool
End Relief angle:
Angle ground from the nose of the tool

26. Cutting-Tool Terms Cutting edge angle End Cutting edge angle
Ground on a tool so that it can be mounted in the correct position for various machining operations.
Side Cutting edge angle
Allows flank of the tool to approach the work piece first
Spreads the material over a greater distance on the cutting edge, thereby thinning out the chip.
Approximately 150
End Cutting edge angle
Allows the cutting tool to machine close to the work piece during turning operations
Usually 20 – 300

27. Cutting-Tool Terms Rake angle: Back Rake angle Side Rake angle
Ground on a tool to provide a smooth flow of the chip over the tool so as to move it away from the work piece
Back Rake angle
Ground on the face of the tool
Influences the angle at which chip leaves the nose of the tool
Generally
Side Rake angle
Ground on the tool face away from the cutting edge
Influences the angle at which the chip leaves the work piece
A lathe tool has 140 side rake.

28. Side Rake Large as possible to allow chips to escape Amount determined
Type and grade of cutting tool
Type of material being cut
Feed per revolution
Angle of keenness
Formed by side rake and side clearance

29. Back Rake Angle formed between top face of tool and top of tool shank
Positive
Top face slopes downward away from point
Negative
Top face slopes upward away from point
Neutral

30. Rake Angles Small to medium rake angles cause: high compression
high tool forces
high friction
result = Thick—highly deformed—hot chips

31. Negative Rake Tools
Typical tool materials which utilize negative rakes are:
Carbide
Diamonds
Ceramics
These materials tend to be much more brittle than HSS but they hold superior hardness at high temperatures. The negative rake angles transfer the cutting forces to the tool which help to provide added support to the cutting edge.

32. Cutting-Tool Terms Nose Radius: Rounded tip on the point of the tool
Functions:
Strengthens finishing point of tool
Improves surface finish on work
Should be twice amount of feed per revolution
Too large – chatter; too small – weakens point

33. Tool Angle Application
Factors to consider for tool angles
The hardness of the metal
Type of cutting operation
Material and shape of the cutting tool
The strength of the cutting edge