Drilling
process
Turning
process
Welding
process
Sheet metal
process
CAM
3/16/2016
ME 1001 Unit-3 Lecture -1
1
3/16/2016
ME 1001 Unit-3 Lecture -1
2
Sheet metal process
Rolled metals of gauge 10 to 20 are
considered as sheet metals
 The metals include steel, copper,
brass,aluminium,zinc etc.

3/16/2016
ME 1001 Unit-3 Lecture -1
3
Sheet metal operations
Major classifications include
 1.Shearing

◦
◦
◦
◦
Blanking
Piercing
Punching
Notching
2.Bending
 3. Drawing

3/16/2016
ME 1001 Unit-3 Lecture -1
4
Shearing
3/16/2016
ME 1001 Unit-3 Lecture -1
5
Shearing
Two or more blades are used for cutting
the sheet at multiple or single point
 Pressure is generally applied on the top
blade causing the shear force which tears
the sheet.
 The amount of force is applied on the
system using a hydraulic press or
mechanical press

3/16/2016
ME 1001 Unit-3 Lecture -1
6
Blanking
3/16/2016
ME 1001 Unit-3 Lecture -1
7
Blanking
Instead of blades a blanking press shape is
used in this process.
 Once the sheet metal is inserted in
between the blanking die and the punch
high pressure is applied on the punch
 The output component is ejected from
the die and the scrap is taken out

3/16/2016
ME 1001 Unit-3 Lecture -1
8
Piercing and punching
3/16/2016
ME 1001 Unit-3 Lecture -1
9
Piercing and punching
Similar to the blanking operation but at
multiple points.
 The scrap is the blanked components and
the remaining sheet is the finished
product.

3/16/2016
ME 1001 Unit-3 Lecture -1
10
Notching
3/16/2016
ME 1001 Unit-3 Lecture -1
11
Notching
 This
is a process of removing
metal into to the desired
shape from the side or edge of
the sheet
3/16/2016
ME 1001 Unit-3 Lecture -1
12
Bending
Types of bending
 Edge bending
 V- bending
 U- bending

3/16/2016
ME 1001 Unit-3 Lecture -1
13
Edge bending
3/16/2016
ME 1001 Unit-3 Lecture -1
14
V- bending
3/16/2016
ME 1001 Unit-3 Lecture -1
15
U bending and channel bending
3/16/2016
ME 1001 Unit-3 Lecture -1
16
Spring back effect in sheet metals
3/16/2016
ME 1001 Unit-3 Lecture -1
17
Drawing – sheet metal
3/16/2016
ME 1001 Unit-3 Lecture -1
18
3/16/2016
ME 1001 Unit-3 Lecture -1
19
Sheet metal presses
Classified into
 Manually operated press

◦ Fly press
◦ Power presses
◦ Mechanical press
◦ Hydraulic press
◦ Pneumatic press
3/16/2016
ME 1001 Unit-3 Lecture -1
20
Manual press
3/16/2016
ME 1001 Unit-3 Lecture -1
21
Mechanical press
3/16/2016
ME 1001 Unit-3 Lecture -1
22
Pneumatic press
3/16/2016
ME 1001 Unit-3 Lecture -1
23
Hydraulic press
3/16/2016
ME 1001 Unit-3 Lecture -1
24
3/16/2016
ME 1001 Unit-3 Lecture -1
25
Joining methods

Welding
◦ Fusion
◦ Brazing
◦ Soldering
3/16/2016
ME 1001 Unit-3 Lecture -1
26
Definition
Process of joining similar metals by
application of heat
 With or without application of pressure
 With or without application of filler
material


Permanent joints can be produced using
welding
3/16/2016
ME 1001 Unit-3 Lecture -1
27
Classifications











Gas welding
Oxy acetylene welding
Oxy hydrogen welding
Arc welding
Metal electrode welding
Carbon electrode welding
Resistance welding
Spot welding
Seam welding
Projection welding
Butt welding
3/16/2016
ME 1001 Unit-3 Lecture -1
28
Terminology
Base metal: work piece or part to be
joined.
 Weld bead: material deposited by
welding process
 Puddle :portion of base metal at the
joint
 Weld pass: movement of welding torch
or arc from one end to other
 Tack weld: temporary welding done at
the ends

3/16/2016
ME 1001 Unit-3 Lecture -1
29
Weld bead
3/16/2016
ME 1001 Unit-3 Lecture -1
30
Puddle
3/16/2016
ME 1001 Unit-3 Lecture -1
31
Tack weld
3/16/2016
ME 1001 Unit-3 Lecture -1
32
Gas welding
It is a fusion welding process
 Heat melts the parent metal and fuses
with the filler metal which are in molten
stage
 Suitable for the sheets having thickness 2
to 50 mm and materials having thickness
15 mm
 Filler materials generally in the form of
rods which can melt and form as filler and
creates a flux bond

3/16/2016
ME 1001 Unit-3 Lecture -1
33
Process
3/16/2016
ME 1001 Unit-3 Lecture -1
34
Equipment
3/16/2016
ME 1001 Unit-3 Lecture -1
35
Combustion cycle of oxyacetylene
flame
2
C2H2 + 5 O2 = 4 CO2 + 2
H2O + heat (300Kcal/mole)
Temperature
ranges to
3300 deg c
3/16/2016
ME 1001 Unit-3 Lecture -1
36
Flame types
3/16/2016
ME 1001 Unit-3 Lecture -1
37
3/16/2016
ME 1001 Unit-3 Lecture -1
38
Arc welding
Also known as metal electrode welding
 Classified into two
 Metal arc welding
 Carbon arc welding

3/16/2016
ME 1001 Unit-3 Lecture -1
39
Working
The work piece is clamped with a cable
which is the cathode (-) terminal.
 The arc is connected to the anode (+)
terminal of the Dc supply.
 When these two are brought together at
a distance of the 2-4mm the current
continues to flow causing the plasma , and
an electric arc is formed which fuses the
two base metals

3/16/2016
ME 1001 Unit-3 Lecture -1
40
Working
Approximately 1Kwh of electricity will a
heat of around 1000j of heat .
 The temperature of the arc is around
6000 to 7000 deg c

3/16/2016
ME 1001 Unit-3 Lecture -1
41
Metal arc welding process
3/16/2016
ME 1001 Unit-3 Lecture -1
42
Arc welding equipment
Comprises of the following components
 Power source (AC or DC)
 Electrode
 Electrode holder
 Ground clamp
 Cabels

3/16/2016
ME 1001 Unit-3 Lecture -1
43
Diagrammatic view
3/16/2016
ME 1001 Unit-3 Lecture -1
44
Pictorial view
3/16/2016
ME 1001 Unit-3 Lecture -1
45
Arc welding power sources
Transformer (AC)
 Rectifier (AC to DC)
 Generator (AC or DC)

3/16/2016
ME 1001 Unit-3 Lecture -1
46
Polarities
Work piece can be interchanged between
cathode and anode and similarly the
electrode
 If the electrode is anode and work piece
is clamped to cathode it is called ‘Straight
polarity’
 If the electrode is cathode and the work
piece is anode it is reverse polarity

3/16/2016
ME 1001 Unit-3 Lecture -1
47
Electrodes
Bifurcated into two variants
 Consumable or cruisible electrode
 Non consumable

3/16/2016
ME 1001 Unit-3 Lecture -1
48
Consumable electrode
3/16/2016
ME 1001 Unit-3 Lecture -1
49
3/16/2016
ME 1001 Unit-3 Lecture -1
50
Properties of flux coating
Gas shielding
 Slag
 Arc stabilizing
 De oxidizing the weld

3/16/2016
ME 1001 Unit-3 Lecture -1
51
Cleaning tools
Chipping hammer
 Metal wire brush

3/16/2016
ME 1001 Unit-3 Lecture -1
52
Welding techniques
Forehand welding
 Backhand welding

3/16/2016
ME 1001 Unit-3 Lecture -1
53
Forehand welding
3/16/2016
ME 1001 Unit-3 Lecture -1
54
Backhand welding
3/16/2016
ME 1001 Unit-3 Lecture -1
55
3/16/2016
ME 1001 Unit-3 Lecture -1
56
Types of welding joints
3/16/2016
ME 1001 Unit-3 Lecture -1
57
Resistance welding
3/16/2016
ME 1001 Unit-3 Lecture -1
58
Soldering and brazing
Both are liquid based bonding processes
 Soldering
 Method of joining two are more pieces of
metal by a means of fusible alloy, which is
called as the solder
 Flux is added to prevent the oxidation of
metals during the process

3/16/2016
ME 1001 Unit-3 Lecture -1
59
Steps in soldering process
Shaping the parts to be joined
 Removal of dirt and grease
 Flux application on the surfaces
 Application of molten solder for wetting

3/16/2016
ME 1001 Unit-3 Lecture -1
60
3/16/2016
ME 1001 Unit-3 Lecture -1
61
Brazing
Process of joining two dissimilar metals in
which metals are heated to a suitable
temperature and filler material in the
molten form is applied
 In this flux may or may not be used

3/16/2016
ME 1001 Unit-3 Lecture -1
62
DRILLING
3/16/2016
ME 1001 Unit-3 Lecture -1
63
Drilling
Process of making a circler cut in the
work piece.
 The tool in the drilling process is much
harder than the work piece

3/16/2016
ME 1001 Unit-3 Lecture -1
64
Classification
Bench drilling machine
 Sensitive drilling machine
 Radial drilling machine
 Gang drilling machine
 Multi spindle type
 Deep hole drilling machine
 Transfer drilling

3/16/2016
ME 1001 Unit-3 Lecture -1
65
Sensitive drilling machine
3/16/2016
ME 1001 Unit-3 Lecture -1
66
components
Spindle
 Sleeve
 Column
 Head
 Work table
 Base
 Drill feed

3/16/2016
ME 1001 Unit-3 Lecture -1
67
Radial drilling machines
3/16/2016
ME 1001 Unit-3 Lecture -1
68
Operations using drilling machine
Counter boring
 Drilling
 Tapping
 Boring
 Reaming
 Counter sinking

3/16/2016
ME 1001 Unit-3 Lecture -1
69
Counter boring

Counter boring: A counter bore
(symbol: ⌴) is a cylindrical flat-bottomed
hole that enlarges another coaxial hole,
or the tool used to create that feature.
3/16/2016
ME 1001 Unit-3 Lecture -1
70
3/16/2016
ME 1001 Unit-3 Lecture -1
71
Tapping
3/16/2016
ME 1001 Unit-3 Lecture -1
72
Boring
3/16/2016
ME 1001 Unit-3 Lecture -1
73
Reaming

Reaming : Process of sizing and finishing
the already drilled hole.
3/16/2016
ME 1001 Unit-3 Lecture -1
74
Counter sinking
A countersink (symbol: ⌵) is a conical hole
cut into a manufactured object, or the cutter
used to cut such a hole.
 A common use is to allow the head of a
countersunk bolt or screw, when placed in
the hole, to sit flush with or below the
surface of the surrounding material (by
comparison, a counter bore makes a flatbottomed hole that might be used with a
socket-head cap screw).

3/16/2016
ME 1001 Unit-3 Lecture -1
75
Counter sinking
3/16/2016
ME 1001 Unit-3 Lecture -1
76
Nomenclature of twist drill
3/16/2016
ME 1001 Unit-3 Lecture -1
77
Drill holding device
3/16/2016
ME 1001 Unit-3 Lecture -1
78
Drill supporting devices
Helps in holding the work piece which is
under operating at the arrest position.
 Classified into two

◦ Vice mounting
◦ Table or Base mounting
3/16/2016
ME 1001 Unit-3 Lecture -1
79
Vice mounting
3/16/2016
ME 1001 Unit-3 Lecture -1
80
Table mounting
3/16/2016
ME 1001 Unit-3 Lecture -1
81
Operating conditions in drilling

Cutting Speed (v):It’s the peripheral speed of the drill
v = *D*N where
D = dia of the drill in m
N = Speed of rotation in rpm
Feed Rate (f):It’s the movement of drill along the axis (mm/rev)
Depth of Cut (d):The distance from the machined surface to the drill
axis
d=D/2
3/16/2016
ME 1001 Unit-3 Lecture -1
82
Material Removal Rate:It’s the volume of material removed by the drill per unit time
MRR = ( D2 / 4) * f * N mm3 / min
Machining Time (T) :It depends upon the length (l) of the hole to be drilled , to
the Speed (N) and feed (f) of the drill
t = L / (f N) min
Time required to drill : D t/ 1000*feed*cutting speed
3/16/2016
ME 1001 Unit-3 Lecture -1
83
Numerical

Three holes of diameter 15mm are to be
drilled on a 15mm thick plate if the
cutting speed is 30meters per minute.
Calculate the time required to complete
12 such plates assuming the feed
=0.12mm/rev
3/16/2016
ME 1001 Unit-3 Lecture -1
84
TURNING
PROCESS
LATHE MACHINE
3/16/2016
ME 1001 Unit-3 Lecture -1
85
Turning process
The process of material removal for
making the desired shape out of a work
piece is called turning.
 In this process the work piece will be
held in a holding device and rotated
against a work piece at stationary.

3/16/2016
ME 1001 Unit-3 Lecture -1
86
Lathe machine

It’s a machine tool used for shaping the
work piece firmly and rotate or turned,
while the cutting tool advances into the
work causing the material removal or
cutting action.
3/16/2016
ME 1001 Unit-3 Lecture -1
87
Photographic view
3/16/2016
ME 1001 Unit-3 Lecture -1
88
Line diagram of lathe
3/16/2016
ME 1001 Unit-3 Lecture -1
89
Components of lathe machine
Bed
 Head stock
 Saddle
 Tail stock
 Carriage
 Spindle
 Gear box
 Tool post
 Lead screws
 Leg
 Chuck

3/16/2016
ME 1001 Unit-3 Lecture -1
90
Specifications of lathe machine
Swing – max dia that can be machined
 Distance b/w head and tail stock
 Length of bed
 Horse power of the motor
 Cutting speed range
 Screw cutting range
 Feed range
 Accuracy achievable
 Number of tool handling capacity

3/16/2016
ME 1001 Unit-3 Lecture -1
91
Classification
Speed lathes
 Engine lathes
 Bench lathes
 Tool room lathes
 Turret lathes
 Center lathes
 Capstan lathes

3/16/2016
ME 1001 Unit-3 Lecture -1
92
Head stock
3/16/2016
ME 1001 Unit-3 Lecture -1
93
Bed
3/16/2016
ME 1001 Unit-3 Lecture -1
94
Saddle
3/16/2016
ME 1001 Unit-3 Lecture -1
95
Tail stock
3/16/2016
ME 1001 Unit-3 Lecture -1
96
Tool post
3/16/2016
ME 1001 Unit-3 Lecture -1
97
Chuck
3/16/2016
ME 1001 Unit-3 Lecture -1
98
Types of chucks
Universal scroll chuck
 Independent jaw chuck
 Drill chuck
 Magnetic chuck
 Collet chuck

3/16/2016
ME 1001 Unit-3 Lecture -1
99
Lathe centers
Supporting devices for the work piece
 Most of them will have a tapered point
with 60 deg
 These are classified into
 Live center – which rotates along with
work piece
 Dead center – which does not

3/16/2016
ME 1001 Unit-3 Lecture -1
10
0
classification of centers
Male center
 Half male center
 Female center
 V center
 Ball bearing center or Male live center
 Self driving center
 Pipe center

3/16/2016
ME 1001 Unit-3 Lecture -1
10
1
Tool
Some important characteristics of tool
are .
1. high hardness
2. Hot hardness
3. Wear resistance
4. Toughness
5. Low friction
6. Thermal characteristics

3/16/2016
ME 1001 Unit-3 Lecture -1
10
2
Single point cutting tool

Tool which has only one cutting point
action proceeding at one time.
3/16/2016
ME 1001 Unit-3 Lecture -1
10
3
3/16/2016
ME 1001 Unit-3 Lecture -1
10
4
Tool types based on operations
Turning operation
 Threading tool
 Parting tool or cut off tool
 Grooving tool
 Form tool
 Chamfering tool
 Knurling tool

3/16/2016
ME 1001 Unit-3 Lecture -1
10
5
Operation conditions
Cutting speed
 S= peripheral speed

◦
◦
◦
◦
=πDN/1000 m/min
D= dia of the work piece
N= revolutions of the chuck
Since the material passes the stationary
cutting tool with its peripheral speed
◦ So V = S
◦ V= πDN/1000
3/16/2016
ME 1001 Unit-3 Lecture -1
10
6
Operation conditions
Feed:
 Termed as the applied distance and the tool bit
advances along the work distance.






Depth of cut:
Termed as the perpendicular distance that the
tool moves into the work piece
Given by D= (D1-D2)/2 mm
D1 is the initial dia of the work piece
D2 is the final dia of the work piec
3/16/2016
ME 1001 Unit-3 Lecture -1
10
7
Operation conditions
Metal removal rate:
 MRR is the volume of the material
removed in a unit time interval
 MRR= πDdFNcubic mm/min

Interms of the cutting spee
 MRR= 1000vdF
 D= initial dia of the work piece
 d = final dia of the work piece
 F= feed
 N=RPM

3/16/2016
ME 1001 Unit-3 Lecture -1
10
8
Taper turning
Let D1 is the major dia
 And D2 is the minor dia
 L be the total length of the taper
 alpha α be the angle of the taper
 Then tan α = (D1-D2)/2L

3/16/2016
ME 1001 Unit-3 Lecture -1
10
9
Different operations on lathe
3/16/2016
ME 1001 Unit-3 Lecture -1
11
0