i hope, it will helpful to the students and peoples in the search of topics mentioned it is informative to study to even get passing marks or for revision

1. Lathe
By
Priyanka Singh
M.Tech (Applied Mechanics)
Motilal Nehru National Institute of Technology, Allahabad

5. Lathe
 A lathe is a large machine that rotates the work, and cutting is done with a non-
rotating cutting tool. The shapes cut are generally round, or helical. The tool is
typically moved parallel to the axis of rotation during cutting.
 Head stock - This end of the lathe contains the driving motor and gears. Power
to rotate the part is delivered from here. This typically has levers that let the
speeds and feeds be set.
 Tail stock – It is mounted on the right hand side of the bed, can move on guide
ways towards or away form head stock. This can be used to hold the other end of
the part.

6. Lathe
 Carriage: The carriage holds and supports the cutting tool and provide various
movement for generating various surfaces in jobs. It has five main parts:
a) Tool post
b) Compound rest
c) Cross slide
d) Saddle
e) Apron
 Ways - These are hardened rails that the carriage rides on.
 Bed - this is a bottom pan on the lathe that catches chips, cutting fluids, etc.
 Lead screw - A large screw with a few threads per inch used for cutting threads.
It has ACME threads with included angle of 29o for easy engagement and
disengagement of half nut.

7. Lathe
 Lead rod - a rod with a shaft down the side used for driving normal cutting
feeds.
 The critical parameters on the lathe are speed of rotation (speed in RPM) and
how far the tool moves across the work for each rotation (feed in IPR)

8. General classifications used when describing lathes
 Swing - the largest diameter of work that can be rotated.
 Distance Between Centres - the longest length of workpiece
 Length of Bed - Related to the Distance Between Centres
 Power - The range of speeds and feeds, and the horsepower available

9. Facing
 Facing - The end of the part is turned to be square.

10. Turning
 Turning - produces a smooth and straight outside radius
on a part.

11. Turning

12. Formula for Turning
 Depth of cut,
 Average diameter of workpiece,
 Cutting Time,
 Metal Removal Rate,
 Cutting Speed,

  1 2D D
d DOC mm
2

 1 2
avg
D D
D mm
2
 

L A O
CT
fN
   
  
2 2
1 2
avg
D D
MRR D dfN
4 / fN
min/,
1000
1
m
ND
V



13. Tapering
 Tapering - the tool is moves so as to cut a taper (cone
shape).

14. Parting/Slotting/Grooving
 A tool is moved in/out of the work. shallow cut will leave
a formed cut, a deep cut will cut off the unsupported
part.

15. Drilling/Boring
 Drilling/Boring - a cutter or drill bit is pushed into the
end to create an internal feature.

16. Threading
 Threading - The cutting tool is moved quickly cutting
threads.

18. Threading
 In one revolution of the spindle, carriage must travel
the pitch of the screw thread to be cut.
    traingearcarriagetospindleofratiogear
screwleadtheofstartofNumber
cutbetothreadscrewtheofstartofNumber
screwleadtheofPitchL
cutbetothreadscrewtheofPitch
Lscg
L
s
LLss
NNi
z
z
P
LzNPzN







19. Knurling
 Knurling is a manufacturing process whereby a visually-
attractive diamond-shaped (criss-cross) pattern is cut or
rolled into metal.
 This pattern allows human hands or fingers to get a
better grip on the knurled object than would be provided
by the originally-smooth metal surface.

20. Reaming
 A reamer enters the workpiece axially through the end
and enlarges an existing hole to the diameter of the
tool. Reaming removes a minimal amount of material
and is often performed after drilling to obtain both a
more accurate diameter and a smoother internal
finish.

21. Tapping
 A tap enters the workpiece axially through the end and
cuts internal threads into an existing hole. The
existing hole is typically drilled by the required tap
drill size that will accommodate the desired tap.

22. Work holding Devices for Lathes
 Held between centers
 3 jaw self centering chuck (Disc type jobs being held in chucks )
 4 jaw independently adjusted chuck
 Held in a collet (Slender rod like jobs being held in collets )
 Mounted on a face plate (Odd shape jobs, being held in face plate)
 Mounted on the carriage
 Mandrels
 Magnetic chuck – for thin job

23. Lathe chucks
 Lathe chucks are used to support a wider variety of workpiece
shapes and to permit more operations to be performed than can
be accomplished when the work is held between centers.
 Three-jaw, self-centering chucks are used for work that has a
round or hexagonal cross section.
 Each jaw in a four-jaw independent chuck can be moved inward
and outward independent of the others by means of a chuck
wrench. Thus they can be used to support a wide variety of work
shapes.
 Combination four-jaw chucks are available in which each jaw can
be moved independently or can be moved simultaneously by
means of a spiral cam.

24. 3 Jaw Chuck 4 Jaw Chuck

25. Collets Magnetic Chuck
Face Plate

26. Errors in tool settings
 Setting the tool below the centre decrease actual rake angle,
while clearance angle increases by the same amount. Thus
cutting force increased.
 Setting the tool above the centre causes the rake angle to
increase, while clearance angle reduces. More rubbing with
flank.

27. Type of Lathe
 Central lathe
 Turret lathe
 Capstan lathe
 Automatic lathe
 Special purpose lathe

28. Turret Lathe
A turret lathe, a number of tools can be set up on the
machine and then quickly be brought successively into
working position so that a complete part can be
machined without the necessity for further adjusting,
changing tools, or making measurements.

29. Turret Lathe

30. Capstan Lathe

31. Capstan lathe Turret lathe
Short slide, since the saddle is
clamped on the bed in position.
Saddle moves along the bed,
thus allowing the turret to be of
large size.
Light duty machine, generally for
components whose diameter is
less than 50 mm.
Heavy duty machine, generally
for components with large
diameters, such as 200 mm.
Too much overhang of the turret
when it is nearing cut.
Since the turret slides on the
bed, there is no such
difference.
Ram-type turret lathe, the ram
and the turret are moved up to
the cutting position by means of
the capstan Wheel. As the ram is
moved toward the headstock, the
turret is automatically locked into
position.
Saddle-type lathes, the main
turret is mounted directly on
the saddle, and the entire
saddle and turret assembly
reciprocates.

32. Automatic Lathe
 The term automatic is somewhat loosely applied, but is
normally restricted to those machine tools capable of
producing identical pieces without the attention of an
operator, after each piece is completed. Thus, after
setting up and providing an initial supply of material,
further attention beyond replenishing the material
supply is not required until the dimensions of the work
pieces change owing to tool wear.
 A number of types of automatic lathes are developed
that can be used for large volume manufacture
application, such as single spindle automatics, Swiss type
automatics, and multi-spindle automatics.

33. Swiss type Automatic Lathe Or Sliding Headstock Automatics
 Headstock travels enabling axial feed of the bar stock
against the cutting tools.
 There is no tailstock or turret
 High spindle speed (2000 – 10,000 rpm) for small job
diameter
 The cutting tools (upto five in number including two on
the rocker arm) are fed radially
 Used for lot or mass production of thin slender rod or
tubular jobs, like components of small clocks and wrist
watches, by precision machining.

35. Multi Spindle Automatic Lathe
 For increase in rate of production of jobs usually of
smaller size and simpler geometry.
 Having four to eight parallel spindles are preferably used.
 Multiple spindle automats also may be parallel action or
progressively working type.

37. Shaper and Planner
By
Vineet Kumar Mishra
M.Tech (Fluid and Thermal)
Indian Institute of technology Guwahati

38. Shaper
Construction of shaper
Shaper has different parts
included to perform cutting
operations. It includes
principal parts as
1. Base
2. Column
3. Cross-rail
4. Saddle
5. Table
6. Ram
7. Tool-head.

39. Base
Base is the bed or support part
of the machine, which can be
rigidly bolted to the floor.
Column
It is a box type structure,
serving as housing for the
driving mechanism and power
transmission unit.
Crossrail
It is mounted on the vertical
guideways on the front of
column, it has two parallel
guideways which are
perpendicular to the axis of
Ram and gives support to
saddle as well as table.
Saddle
It is an unit provided on the Crossrail to hold the table on its top. Crosswise movement is
produced by rotating cross feed screw which is provided in Crossrail and saddle.

40. Shaper
Table: It is a boxlike casting which T-slots on its horizontal as well as vertical
faces to clamp the work. It gets movement from Crossrail. In case of heavier
table or large unit shaper table is supported with adjustable sliding support. In
universal shaper table may be swivelled on a horizontal axis and the upper part
may be tilted up or down.
Ram: Ram is a type of tool holding device which reciprocates on the dovetail
guideways provided over the column. It is heavily ribbed to make it more
rigid. It has an inside housing which with some mechanism is connected with
the reciprocating mechanism inside column, it is known as quick return
mechanism. It has a screw shaft to alter the position or working with respect to
the workpiece. At the extreme end there is a tool holder fitted with it.
Tool head: The tool head of the shaper is used to hold the tool rigidly and
keep the tool away from work piece during return stoke. The tool head also
provides adjustment and feed motion to the tool, either vertical or at a certain
angle.

41. Shaper
 The relative motions between the tool and the workpiece,
shaping and planning use a straight-line cutting motion with
a single-point cutting tool to generate a flat surface.
 The shaping machine is used to machine flat metal surfaces
especially where a large amount of metal has to be removed.
It is also used to produce grooves, slots and keyways,
producing contour, concave or combination of these.
 Relatively skilled workers are required to operate shapers and
planers, and most of the shapes that can be produced on
them also can be made by much more productive processes,
such as milling, broaching, or grinding.

42. Shaper

43. Quick return motion Mechanism

44. Quick return motion Mechanism
 In shaping, the cutting tool is held in the tool post
located in the ram, which reciprocates over the work
with a forward stroke, cutting at velocity V and a quick
return stroke at velocity VR.
 The rpm rate of the drive crank (Ns) drives the ram and
determines the velocity of the operation.
 The stroke ratio,  0
360
s
cutting stroke angle
R

45. Classification of Shaper Machine
Shapers, as machine tools usually are classified
according to their general design features as follows,
1. Horizontal
a. Push-cut
b. Pull-cut or draw cut shaper
2. Vertical
a. Regular or slotters
b. Keyseaters
3. Special purpose

46. Formula
 Cutting speed,
 Number of strokes,
 Time of one stroke,
 Total time,


(1 )
1000
NL m
V
s
w
N
f


(1 )
min
1000
L m
t
V
(1 ) (1 )
min
1000 1000
s
L m Lw m
T N
v vf
 
 

47. Hydraulic Shaper

48. Advantages of hydraulic shaping
 1. Cutting speed remains constant throughout most of the cutting
stroke, unlike the crank shaper where the speed changes continuously.
 2. Since the power available remains constant throughout, it is possible
to utilise the full capacity of the cutting tool during the cutting stroke.
 3. The ram reverses quickly without any shock due the hydraulic
cylinder utilised. The inertia of the moving parts is relatively small.
 4. The range and number of cutting strokes possible are relatively large
in hydraulic shaper.
 5. More strokes per minute can be achieved by consuming less time for
reversal and return strokes.

49. Planer
 A planer is the same machine as shaper used to produce
plane surface by the use of single point cutting tool. It is
very large unit or machine compared to shaper to produce
large surfaces. Basic difference between shaper and planer is
as in planer work is set to reciprocates while feed is done by
the lateral movement of cutting tool but in shaper cutting
tool mounted on ram reciprocates and work is moved.
 Planing is much less efficient than other basic machining
processes, such as milling, that will produce such surfaces.
 Planing and planers have largely been replaced by planer
milling machines or machines that can do both milling and
planing.

50. Principal parts of a planer
1. Bed
2. Table or platen
3. Tool head
4. Crossrail
5. Housing or column
6. Driving and feed mechanism
Planer

51.  Bed: Bed is a box like structure having cross ribs, it is large and heavy to support columns and
give rigidity and stability to the reciprocating units. Usually, length of bed is twice the length of
table so that entire length of the table can be covered during motion. On the upper surface of the
bed
 Table: Table of a planer is same as table of a shaper, it is also a heavy good quality cast iron made
unit to provide support to the workpiece. T-slots are provided on the entire length of the table to
provide provision to work-holding devices to get installed over it. v-shaped guideways are
provided on entire length.
 Housing: It refers to the two columns attached or fastened on the sides of the bed. These are
heavily ribbed box like rigid structures to compensate cutting forces. These are extruded with
guideways for the up and down moment to the Crossrail along with which side tool heads also
moves. The housing encloses Crossrail elevating screw, vertical and cross feed screws for tool
heads and counter balancing weight for Crossrail.
 Crossrail: It is a box like casting connecting the two housings, ensures the rigidity of machine. It
is mounted on the guideways provided on the columns can be moved up and down on the columns
and at required position it is clamped. Planer is used to produce plane surface hence Crossrail
should remain absolutely parallel to the table and hence movement should be equal for both the
columns. Crossrail has guideways on facing part for tool heads, which can be moved vertical and
horizontal by the help of vertical and horizontal cross feed screws. There is one more screw
housed in it for elevating the rail.
 Tool-head: Tool head of a planer is similar to that of shaper, both in construction and operation.
Planer

52. Planer

53. Difference between Shaper and Planer
Shaper Planer
 In this machine tool work
table is stationary and tool
reciprocates.
 Used for smaller work piece.
 Can not take deeper cut.
 At a time one tool will work.
 It is light, less rigid and
cheaper machine tool.
 In this machine tool work
table reciprocates and tool is
stationary.
 Used for large work piece.
 Planer can take deeper cut.
 More than one cutting tools
work at a time.
 It is heavier, more rigid and
costier machine tool.

55. Milling
By
Vineet Kumar Mishra
M.Tech (Fluid and Thermal)
Indian Institute of technology Guwahati

56. Milling
Milling machines of various types are widely used
for the following purposes using proper cutting
tools called milling cutters:
 Flat surface in vertical, horizontal and inclined planes
 Making slots or ribs of various sections
 Slitting or parting
 Often producing surfaces of revolution
 Making helical grooves like flutes of the drills
 Long thread milling on large lead screws, power screws,
worms etc and short thread milling for small size
fastening screws, bolts etc.

57. Milling
 2-D contouring like cam profiles, clutches etc and 3-D
contouring like die or mould cavities
 Cutting teeth in piece or batch production of spur gears,
straight toothed bevel gears, worm wheels, sprockets,
clutches etc.
 Producing some salient features like grooves, flutes,
gushing and profiles in various cutting tools, e.g., drills,
taps, reamers, hobs, gear shaping cutters etc.

58. Up milling and down milling

59. Up milling and down milling
 In down milling, though the cut starts with a full chip
thickness, the cut gradually reduces to zero. This helps in
eliminating the feed marks present in the case of up
milling and consequently better surface finish.
 Climb milling also allows greater feeds per tooth and
longer cutting life between regrinds than the
conventional milling.
 Up milling needs stronger holding of the job and down
milling needs backlash free screw-nut systems for
feeding.

60. Advantages of Down Milling
1. Suited to machine thin and hard-to-hold parts since
the workpiece is forced against the table or holding
device by the cutter.
2. Work need not be clamped as tightly.
3. Consistent parallelism and size may be maintained,
particularly on thin parts.
4. It may be used where breakout at the edge of the
workpiece could not be tolerated.
5. It requires upto 20% less power to cut by this method.
6. It may be used when cutting off stock or when milling
deep, thin slots.

61. Disadvantages of Down Milling
1. It cannot be used unless the machine has a backlash
eliminator and the table jibs have been tightened.
2. It cannot be used for machining castings or hot rolled
steel, since the hard outer scale will damage the cutter.

62. Classification of milling machines
(a) According to nature of purposes of use:
 General purpose
 Single purpose
 Special purpose
(b) According to configuration and motion of the
work-holding table / bed
 Knee type
 Bed type
 Planer type
 Rotary table type

63. Classification of milling machines
(c) According to the orientation of the spindle(s).
 Plain horizontal knee type
 Horizontal axis (spindle) and swiveling bed type
 Vertical spindle type
 Universal head milling machine
(d) According to mechanization / automation and
production rate
 Hand mill (milling machine)
 Planer and rotary table type vertical axis milling machines
 Tracer controlled copy milling machine,
 Milling machines for short thread milling
 Computer Numerical Controlled (CNC) milling machine

64. Classifications of milling cutters
(a) Profile sharpened cutters – where the geometry of
the machined surfaces are not related with the tool
shape, viz;
i. Slab or plain milling cutter: – straight or helical
fluted
ii. Side milling cutters – single side or both sided type
iii. Slotting cutter
iv. Slitting or parting tools
v. End milling cutters – with straight or taper shank
vi. Face milling cutters.

65. Classifications of milling cutters
(b) Form relieved cutters – where the job profile
becomes the replica of the
Tool-form, e.g., viz.;
i. Form cutters
ii. Gear (teeth) milling cutters
iii. Spline shaft cutters
iv. Tool form cutters
v. T-slot cutters
vi. Thread milling cutter

66. Slab or Plain milling cutters

67. Side and slot milling cutters

68. Slitting saw or parting tool

69. End milling cutters or End mills

70. Face milling cutters

71. Use of form relieved cutters (milling)

72. Tool form cutters

73. T- slot cutter

74. Gear teeth milling cutters

75. Spline shaft cutters

76. Straddle milling

77. Gang milling

78. Turning by rotary tools (milling cutters)

79. Indexing

80. Simple or Plain Indexing
 Plain indexing is the name given to the indexing method
carried out using any of the indexing plates in
conjunction with the worm.

81. Milling Velocity
 The cutting speed in milling is the surface speed of the
milling cutter.
DN
V
1000



82. Milling Time
 Time for one pass = minutes
 Approach distance,
L 2 A
fZN
 
 
2 2
D D
A d d D d
2 2
   
       
   

83. MRR in Milling
Considering the parameters defined in the discussion of
speeds and feeds, etc, the MRR is given below,
Where,
MRR =
where, w = width of cut, d = depth of cut
w d F 

84. Some Formulae for Milling
max
a
2
max 2 2
2
Maximum uncut chip thickness (t )
Average uncut chip thickness(t )
Peak to valley surface roughness (h )
4
vg
f d
NZ D
f d
NZ D
f
DN Z




86. Drilling
By
Vineet Kumar Mishra
M.Tech (Fluid and Thermal)
Indian Institute of technology Guwahati

87. Drilling
 Drilling is a operation that cuts cylindrical holes.

88. TYPES OF DRILL PRESSES
 Vertical or pillar type
 Radial Arm type
 Gang drill
 Multi Spindle drill
 Numerical Control drill

89. Drilling Operations

90. Chip formation
of a drill

91. Drill
 The twist drill does most of the cutting with the tip of
the bit.
•There are flutes
to carry the chips
up from the
cutting edges to
the top of the
hole where they
are cast off.

92. Drill

93. Drill
 Axial rake angle is the angle between the face and the line
parallel to the drill axis. At the periphery of the drill, it is
equivalent to the helix angle.
 The lip clearance angle is the angle formed by the portion of
the flank adjacent to the land and a plane at right angles to
the drill axis measured at the periphery of the drill.
 Lead of the helix is the distance measured parallel to the drill
axis, between corresponding point on the leading edge of the
land in one complete revolution.

94. Drill
 Drill sizes are typically measured across the drill points with
a micrometer
 Most widely used material is High Speed Steel
 The drill blanks are made by forging and then are twisted to
provide the torsional rigidity. Then the flutes are machined
and hardened before the final grinding of the geometry.
 Deep hole drilling requires special precautions to take care of
the removal of large volume of chips.

95. Point Angle (2β)
 The point angle is selected to suit the hardness and brittleness of
the material being drilled.
 Harder materials have higher point angles, soft materials have
lower point angles.
 An increase in the drill point angle leads to an increase in the
thrust force and a decrease in the torque due to increase of the
orthogonal rake angle.
 This angle (half) refers to side cutting edge angle of a single point
tool.
 Standard Point Angle is 118°
 It is 116° to 118° for medium hard steel and cast iron
 It is 125° for hardened steel
 It is 130° to 140° for brass and bronze
 It is only 60° for wood and plastics

96. Helix Angle (ψ)
 Helix angle is the angle between the leading edge of the
land and the axis of the drill. Sometimes it is also called
as spiral angle.
 The helix results in a positive cutting rake
 This angle is equivalent to back rake angle of a single
point cutting tool.
 Usual – 20° to 35° – most common
 Large helix : 45° to 60° suitable for deep holes and softer
work materials
 Small helix : for harder / stronger materials
 Zero helix : spade drills for high production drilling
micro-drilling and hard work materials

97. Cutting Speed in Drilling
 The cutting speed in drilling is the surface speed of the
twist drill.
/ min
1000
DN
V m



98. Drilling Time
 Time for drilling the hole
, min
L
T
fN

2
3
, / min
4
D
MRR fN mm
 
  
 
MRR in Drilling

99. Some Formulae for Drilling
 1
( )
2tan
( ) sin
2
( )
2sin
2 / tan
( ) tan
sin
D
Coneheight h
f
Uncut chipthickness t
D
Widthof cut b
r D
Orthogonal rakeangle










 
  
 

100. Lecture:14
Revision of machine tools and
metal cutting
 Lathe Machines
 Planer, Shaper and Slotter Machines
 Milling Machines
 Drilling Machines
 Metal cutting and cutting tool