1. The document describes various common machining processes including lathe operations like turning, taper turning, and thread cutting. 2. Milling operations including plain milling, face milling, and side milling are discussed as well as other processes like drilling, planning, shaping, and grinding. 3. Numerical control and computer numerical control are covered as methods to control machine tools using programmed instructions.

1. MACHINING PROCESS

2. LATHE
• Lathe is the most general purpose machine tool.
• The work piece is held and rotated against suitable cutting tool.
• It has provision to hold the workpiece and to rotate it about an axis.
• If the cutting tool is moved parallel to the axis of rotation of the
work, then a cylindrical surface is produced
• If the tool is moved perpendicular to the axis of rotation of the work,
then flat surface is obtained.

3. lathe

4. PARTS OF LATHE
FEED MECHANISM : LONGITUDINAL, CROSS FEED AND ANGULAR FEED

5. Tail stock
chuck
Lead screw bed

6. carriage Tool post

7. SPECIFICATION OF LATHE
• The overall length of bed
• Largest diameter of the work piece that can be rotated (height of live and
dead center above the bed)
• Distance between the centers (max w/p length)
• Range of spindle speed
• Power rating of electric motor
• Diameter of lead screw and number and range of threads that can be cut.

8. OPERATIONS PERFORMED ON LATHE
1. TURNING- Obtaining cylindrical surface
2. TAPER TURNING
METHODS
1. FORMING TOOL METHODE
HOLDING OF W/P - CHUCK AND LATHE CENTERS

9. 2. TAIL STOCK SET OVER METHODE
The principle of this method is to shift the axis of rotation of the w/p at
an angle to the lathe axis and feeding the tool parallel to the lathe axis.
The taper angle will be twice the inclination of the axis.

10. • 3. COMPOUND REST METHOD
Swiveling angle
should be half of
the taper angle

11. Turning
Taper turning

12. • THREAD CUTTING
Thread can be cut
either on outside or
inside of the w/p called
external and internal
thread respectively
Pitch- lead screw – gear
adjustment

13. Thread cutting

14. • KNURLING
ROUGHENING A SMOOTH
SURFACE

15. knurling

16. SHAPING MACHINE
Function- production of flat
surface
Single point tool
Tool reciprocates
Frwd stroke—cut

17. PRINCIPLE PARTS OF A SHAPER
-----
RAM
Quick return
mechanism---ram
Slower cutting stroke
Faster return stroke

18. Shaping machine

19. Planer Machine
• Planer Machines are used to
produce flat surfaces by a
stationary single point cutting
tool.
• The table on which workpiece
is clamped moves against the
tool.
• The feed is given to the cutting
tool.
• Planer machine is capable of
holding very large workpiece
which cannot be accomodated
by a shaper machine.

20. Slotter Machine
• In slotter machine the
tool reciprocates in
vertical axis.
• Cutting action is only
during the downward
stroke.
• It operates on the
same principle as that
of shaper

21. DRILLING MACHINE
• Drilling is the operation of
making holes in a workpiece
by forcing a rotating tool
called drill against it.
• Main parts are:
 Base
 Column
 Table
 Drill Head

22. Drilling machine

23. OPERATIONS ON DRILLING MACHINE
1. DRILLING (a)
2. REAMING (b)
3. BORING
4. COUNTER BORING (c)
5. COUNTER SINKING (d)
6. TAPING (e)

24. Drilling:
It Is the Operation of producing circular hole using a drill by removing
metal from the workpiece.
Reaming:
It Is the Operation of finishing a hole using a reamer.
Boring:
It Is the Opreation of enlarging a hole.
Counter Boring:
It is the operation of increasing the diameter of a hole for a certain distance.
Counter Sinking:
It is the operation of creating a cone shape at the end of a hole.
Taping:
It is the operation of cutting internal threads by means of a tool called TAP.

25. MILLING
UP MILLING
(Conventional Milling)
DOWN MILLING
(Climb Milling)
• Milling is the process of removing metal by feeding the workpiece
against a rotating multipoint cutter. As the cutter rotates, each
cutting edge removes a small amount of material from the
workpiece.
In up milling the workpiece is fed
against the rotating milling
cutter.
In down milling the workpiece is
fed in the same direction of that
of rotating milling cutter.

26. Milling machine
Milling machines can be classified as
1. Horizontal Milling Machine
2. Vertical Milling Machine

27. Horizontal Milling Machine

28. Vertical Milling Machine

29. MILLING OPERATIONS
1. PLAIN MILLING 2. FACE MILLING

30. • 3. SIDE MILLING 4. END MILLING

31. • 5. T SLOT MILLING 6. ANGULAR MILLING

32. • 7. FORM MILLING 8. GEAR CUTTING

33. GRINDING
Grinding is the process of metal
removal in which the cutting tool used
is an abrasive wheel.
It is used for the following purposes
1. To remove small amount of metal
from workpiece.
2. To obtain better surface finish
3. To machine hard surfaces
4. To sharpen cutting tools

34. Grinding machine

35. TYPES OF GRINDING
• 1. CYLINDRICAL GRINDING
 Grinding wheels
Made of abrasive materials
bonded together.
2 types
1. Natural : sand stone,
emery, diamonds etc.
2. Artificial : silicon
Carbide, Aluminium
oxide, boron carbide
etc.

36. • 2. SURFACE GRINDING 3. FORM GRINDING

37. NC Machines
• It is the method of controlling
manufacturing operations by means
of numerical instructions.
• A programme is prepared by the
programmer after product drawing
and process planning
• This programme is recorded in a
magnetic tape and fed to the control
unit.
• This unit sends signals to the
machine through position command
unit.

38. CNC Machines
• It is the method of controlling
manufacturing operations by
means of a computer.
• A CNC code is generated by the
computer after product drawing
and process planning
• The computer send signals to the
machine as per the CNC code.