machining operations

2. Machining
It is a metal removing operation
from the work piece with the help
of machine tools and cutting tools.
Metal is removed in the form of
chip from the workpiece.

3. Names of commonly used
machine tools:
1. Lathe machines, 6. Milling Machines
2. Drilling machines, 7. Boring Machines
3. Grinders, 8. Metal Cutting Saws
4. Shaping machines, 9. Slotting machines etc.
5. Planning Machines,

4. Lathe Machines

5. Lathe machine

6. Basic principle of a lathe machine :
 Lathe machines are normally used to produce
cylindrical surfaces. The job is held in the chuck
attached to the head stock or between the centers
provided at the head stock or tail stock. The tool is
held on the compound rest. Job is rotated at the
predetermined speed by the head stock. The tool is
moved relative to the workpiece with the help of
carriage, cross slide or compound rest. Desired
quantity of metal is removed in the form of chip from
the work piece.

7. Specification of a lathe machine
A lathe machine is specified by the following
 Height of the centers measured from the lathe bed.
 Swing diameter over bed. This the largest diameter of work
piece which will revolve without touching the bed. It is
equal twice the height of centers from the bed.
 Swing diameter over carriage. It is the largest diameter that
can revolve over the cross-slide. This always less than the
swing diameter over the bed.
 Maximum bar diameter. This is the maximum diameter
that will pass through the head stock spindle.
 Length of the bed.

8. Fig.- Specifications of lathe
machine

9. Classification of Lathe machines
Lathes can be classified into following three types
 Engine Lathes
 Light weight bench engine lathe
 Precision Tool Room lathes
 Gap lathes
 Turret Lathes
 Special Purpose lathes

10. Basic Operations Performed on a Lathe Machine :
1. Turning –Plain turning , Step turning
2. Facing
3. Taper Turning
4. Drilling :
5. Boring :
6. Reaming :
7. Knurling :
8. Forming :
9. Chamfering :
10. Parting Off:
11. Threading or thread cutting

11. Turning

12. Plain turning on lathe machine

13. Fig.- step turning on lathe machine

14. Fig.- Facing on lathe machine

15. Turning on lathe machine

16. FIG.- TAPER TURNING BY
COMPOUND REST METHOD

17. Taper turning by set over method

18. Taper turning by swiveling the
compound rest

19. Taper turning by form tool

20. Eccentric turning on lathe machine

21. FIG.- KNURLING

22. Knurling on lathe machine

23. Knurling on lathe using knurling
tool

24. Knurling tool

25. FIG.- DRILLING AND BORING

26. Drilling on lathe machine

27. Boring on lathe machine

28. Drilling on lathe

29. Boring on lathe

30. Reaming on lathe machine

31. Reaming on lathe using reamer
tool

32. Reamers

33. FIGURE – GROOVING AND PARTING

34. Parting on lathe machine

35. Grooving on lathe

36. Forming on lathe machine

37. Chamfering on lathe machine

38. Threading on lathe

39. Threading on lathe machine

40. Shaping Machines
 A shaper is used for producing relatively
small flat surfaces. A single point tool is
mounted on a tool box fitted to a
reciprocating ram. The job is clamped in a
vice. There is a cutting action in the forward
motion of the tool while the return stroke is
idle. Job is given indexed feed.

41. FIG.- SHAPER

42. Shaper machine

43. Shaper operations
Horizontal cutting
Vertical cutting
Inclined cutting
Irregular cutting

44. HORIZONTAL AND VERTICAL
CUTTING ON SHAPER

45. INCLINED CUTTING ON SHAPER

46. PLANNING MACHINE OR PLANNER
 Planning machines are used for generating large flat
surfaces. These flat surfaces may be horizontal,
vertical or inclined. Planing machines also perform all
the functions that a shaping machine does. The
planning machines handle larger and heavy jobs.
 In planning machines the job is mounted on a table
which moves forward and backward. The tool is held
firmly on the cross rails in the middle of the machine.

47. FIGURE- PLANNER

48. Planer machine

49. FIG.- MACHINING BED ON
PLANNER

50. Diff. between shaper and planer
Planing Machine Shaping Machine
1. Machine is heavy and is used for
producing large surfaces
2. Cutting takes place by
reciprocating the work piece
3. Heavier cuts can be given
4. Several tools can be mounted and
employed at a time
5. Several jobs requiring similar
operations can be machined at a
time
6. Indexed feed is given to the tool
during idle stroke of the work table.
1. Machine is light and only small job
can be produced.
2. Cutting takes place by
reciprocating the tool.
3. Only light cuts can be given.
4. Only one tool is used at a time.
5. Only one job can be taken up at a
time.
6. Indexed feed is given to the job
during idle stroke of the ram.

51. Milling Machine
 In milling machine , milling operation is done. Milling is a
metal removing process by the help of a multitooth (multi
edge) revolving cutting tool. The cutting tool is held on a
spindle called arbour and the work piece is fixed on a table.
 The table reciprocates past the cutting tool and metal
removal takes place. Feed for the next cut and the depth of
the cut are given by the movement of the table. Each tooth
has the same profile. Each tooth after taking a cut comes in
operation after some interval. This allows the tool to cool
down before the next cut takes place.

52. FIG.- UP MIILNG AND DOWN
MILLING

53. FIG.- HORIZONTAL MILLING
MACHINE

54. FIG.- VERTICAL MILLING MACHINE

55. Milling machine

56. Horizontal milling machine

57. Vertical milling machine

58. MILLING OPERATIONS
1. Plain or Slab Milling
2. Face Milling
3. Angular Milling
4. Form Milling
5. Straddle Milling
6. Gang Milling

59. Drilling Machine
Drilling is an operation through
which a drilled hole is produced
in a job. The machine tool used
in this case is called drilling
machine and the cutting tool
used is called a drill bit or drill.

60. FIG.- DRILLING

61. FIG.- TWIST DRILL

62. Hand drill, drill bit

63. Hand drill

64. Bench drilling machine

65. Fig.- Radial drilling machine

66. FIG.- RADIAL DRILLING MACHINE

67. Radial drilling machine

68. Radial milling machine

69. Operation performed on a drill
machine
 Drilling : Operation of producing a cylindrical hole in a solid body by
means of a drill.
 Reaming : Operation of finishing the drilled hole (that is achieving
the closer tolerances and desired surface finish) by means of a reamer.
 Boring : A drilled hole can be enlarged also by means of boring tool on
the drill machine.
 Counter Boring : Enlarging the diameter of the drilled hole only upto
certain depth. For this counter boring tool is used.
 Counter Sinking : It is enlarging the top end of a drilled hole and
giving it a conical shape by the help of a counter sinking tool.
 Spot Facing : Squaring the surface at the top end of a hole to provide a
true seat for the bolt head or collar.
 Tapping : A tap can be rotated inside an already drilled hole to
produce internal threads.

70. FIG.- DRILLING OPERATIONS

71. Grinding
 It is the process of removing material by the abrasive
action of a revolving wheel from the surface of a work
piece, in order to achieve required dimension and
surface finish of the work piece. The wheel used for
this purpose is called grinding wheel. Grinding wheel
consists of sharp crystals called abrasives held together
by a bonding material.

72. Types of grinding machines
Grinding machines are normally put in two categories :
Roughing Grinders
 Bench , pedestral or floor grinders
 Swing frame grinders
 Portable and flexible shaft grinders
 Belt grinder
Precision Grinders
 Cylindrical Grinders (three types)
 Surface Grinders
 Horizontal spindle, reciprocating table surface grinders
 Vertical spindle , reciprocating table surface grinders
 Internal Grinders

73. Common Grinding Operations :-

74. FIG.- INTERNAL GRINDING AND
CENTERLESS GRINDING

75. FIG.-GRINDING OPERATIONS

76. FIG.- SURFACE GRINDING

77. Hand grinder

78. Bench grinder

79. Bench grinder or pedestal grinder

80. Surface grinder

81. Cylindrical grinder

82. Center less grinding machine