Those are:

(1) Smith or hand forging.

(2) Drop forging.
(3) Press forging.
(4) Machine forging or upset forging.
 J J
dvantages
40The Press In
or Q. Q. 4.1.Dr1.o1p
press Fig,
immediately The
gradually The the The
ven press
forging When What
4.1.1 operation forging lower connectedheated MaForging
nufacturing
ctate
forging, of hammer
50.
apacity shows is the
press changes die drop
has is to advantages Technology
after cavity. drop forging?
a
material drop consists called enclosed billet
rangesgreater forging the its hammer
forging blow. shape as or
of Explain of
drop stockis
with forging press
fromdeformation over
accuracy two to
operation. Ram which th
wiforging
final
strokes, torging".
500 drop is ís neat
shape made
to
within movable sketch. over
9000 takesforging down Final to placed drop
in
Fig. the fall
and
tones 0.254 place 4.1.1 stroke upper shape orbetween foraina.
drop lower 4
to -2
and uniformly byand is
0.508mm. Drop : given eltherby dle
droping lower upper
is
number Billet Ram hammer
Mechanism
drop for to connected
forging Lowerdie Upper die
and díe
actionworkpiece gravity
Anvil die or
of cavity.
completely. or punch
punch and or to
working by byanvil
upstroke. some and
means which lower
strokes power
of is
The fixed. die.
series on Processes
Forming
per upstroke the Here
of S-18.
VW-22
minute blows. billet upper
takes W-17
placed die
can Whicn
place in is
be
 Forging
4.1.1.3
Q.Press ()
(ii)Limitations (iv) (ii) (ii)
ingle In Advantages
(i)
drop Explain Difficult MostMaintenance
Quality Very Rate
ous operation,
Afterthe
Horizontal the The upset be
forging, of little of FIg
The Opsetng In
Upset
with to the production
of metal
heated this Explain
bar 4.1.Z
neat
handle times, forgingsamount typeforging
cost forging is or
shows
metal displaced end job machines with
slow sketch of
is
heavy single comparatively is is forging sketch
is
s low of is upset also gtg
flash high. machines
movable placed gripped
ingshaped is
any jobs. pass as from called
forging metal called upset ith
compared is between
three is required. the inupsetters forgirg rieat
die are th e is
macthine
by not interior operation. pressed sketch
ytion. press specified
and fixed operatior
sufficient better. fixed
means to Punch
punch are forging
forging drop and half and
and generally
It
of 4.1.2:Upset
forgingFig. by consistsof gathered
are made It
a to hammers. the movable die.
Thethe involves
series
operations. get withdrawn diameter to hortzontal
Movabledie Fixeddie flow of either
the die applying the
of
blows, final aroundwhich pressure upsetting
at
r to of acting the
their bar
shape. length centre
but that the grips is
initial outside .
i.eoperatton.
Job can firmlybarthe applied wise it
in appears or
press position. be pressure only
shaped. of at at
bar. the inote
forging
when heatedhorizontal to a cd
a
bar
the closed. thusend of
eration uniform direction
In
this causing sectie
S-19, L
methe it
is
 o- Q. Q.4.2.1
Torces PIg. rolls.These
rotating Fig.
4.2.1 Explain State
Explain Rolling
between 4.21 Principle
rollers
shows in rollingRoling is
opposite shows principle
most
the exerts principle
rolling process of
rolls principle of
widely
directions. Rolling
high roling
are of with with used
rectangular
responsible compressive with
of neat neat
roling mechanical
mal e
(Ri
aa
w l sketch. neat sketch.
Bar sketch.
for slab Fig.
Irgot force process.
drawing
working
4.2.1:of on Work
thickness
Principle the
process
out stock in
the the
t1, due used H
metal. which of form
Second
roll First
rolI in rolls
rolling to
squeezing of industry to
after bar increase
or
rolling today.
billet
actions.
in
is is length
reduced These passed
thus
to rollers between
reducing
tz.
Also are W.14S-16
Kaswledge
Tech two
frictional called its
W-17 W-15
rollers cross
as
 4 - 11
ManufacturingTechnology Forming Processe,
Rolling can produce a stock having constant cross-section throughout its length.
channel sections.
It can produce many shapes such as I, T, L, Cand various
rolling is considered as hot rolline
Rolling is done in both i.e. hot rolling and cold rolling. Normally
specified as cold rolling.
4.2.2 Hot Rolling
S-22
Q. Explain hot and cold rolling. State their applications.
state is passed between two rolls revolving at the same speed br
In hot rolling process, the metal in a hot plastic
in opposite direction.
is reduced in thickness and increased in length.
As the metal passes through the rolls, it
rolling first cast into ingots of suitable form i.e. rectangular, square or round. These
The metal provided for hot
then heated in gas fired furnace to attain uniform working temperature.
ingots
for hot rolling processes.
Then these ingots are taken to rolling mills
metal during rolling is continuous and almost in longitudinal direction.
The flow of other
plates, bars, sheets, wide variety of bars and sections, rods and
components like
Hot rolling produces
structural shapes.

4.2.3 Cold Rolling S-22

their applications.
Q. Explain hot and cold rolling. State surfacefinish
good
operation generally performed on products of hot rolling to give
rolling is a finishing
 Punching
Q. ) operations
Cutting(a)
operations
operations.
forming
(b) cutting(a) Press
ExplainExplain
It The The Write operations
is any
alsopunchingpiercing cuttingcutting
four
alled
operations press
operations done
operation
operation
as on
cing working
sheet
with with done are
operations.
also metal
f
tion. neatsketch. on
sketch. the called are
Fig. press
4.3.2 operations
Cutting as classified
shearing
are
)
Shearing(v) Lancing(ivNotching i)
(iü)Blanking(iPunching ()
Cutting : punching, in
operations. two
operations categories
blanking
n
a
notching,

lancing,
by
a
shearing

e. etc.

S-15 W-14 14
$-
 Q.Blanking
Q. () Q.
WhatExplain ExplainExplain
It In Here
punching Punching It
is is is
blanking
the sheetblanking
hole
alsopunchingpiercing
peration metal called
operation. is the is
operation the operation
operation
working,operation operation as
of desired piercing
cuttinga inwith
blanking press with with
neat of
product operation. neatsketch.
flat workingsketch.
producing
shape is Fig. sketch.
considered and
? 4.3.3
from thvarious
e
metal.
sheet Punching/ : metal
as shaped
the
first removed
Piercing holes
step
Waste Desired
product from on
in
the a
the sheet
series
hole metal
of
operations. is by
waste. a
punch
Fig.
and
2.1.1
die.
tnowlionsedge S-15 W-14
shows
S-15 W-14
the
 Forming Processes
ManufacturingTechnology
4- 18
called
Jt Ís similar to punchíng except that the removed or desired product It ís
punched out portion is the
asblank.
The hole and metal lefttbehind is the waste., The operatlon is shown in Fig 4.3.4.

Waste

Desired
product
L.e. blank

Fig.4.3.4:Blanking
(i)Notching
w14
o What is notching operation incase of press operation? S-15
0. Explain notching operation with neat sketches.
of sheet metal is cut from the edge.
Notching is a method, by which small shape or small portion
It removes the desired shape from the side or edge of a sheet or strip.
The notching operation is shown in Fig. 4.3.5 Square notch
V
notch

Edge of strip

Circular notch

Fig. 4.3.5: Notching

(iv) Lancing W-14, S-15

Q Explain lancing operation with sketch.
then one of its side is bent
operation in which any shape or any hole is partially (incomplete) cut and
It isa
metal, so there is no scrap.
downward. No metal is removed from sheet

The Fig. 4.3.6 shows the lancing operation.

Sheet metal

Lanced Cut

Fig. 4.3.6 : Lancing

TechKnowledge
Pub!catigns
 4- 19
Manufacturing Technology Forming Processes
(v) Shearing
Q. Draw neat sketch of shearing operation and describe it in brief. S-14
is more or less
Itis a kind of blanking where straight cuts are made to cut sheet metal parts. The process
similar to cutting material with a pair of scissors.
Work Punch

Shearing
action

Die

Fig. 4.3.7:Shearing
material
applying two equal and opposite stress which exceeds the shear strength of
Theoperation involves 4.3.7.
material is cut or separated by two cutting edges as shown in Fig.
to be cut. Here, the
and Lancing Operation
4.3.2 Difference between Notching S -14

Q. Compare notching and lancing operation.

Lancing
Notching an
operation any shape is cut partially
Sr. No.
small| In lancing
desired shape or cut a the cut portion is bent.
(1) Notching operation removes the sheet, and then
plate.
portion from the edge of removed from sheet, hence
not
No metal is
removed, it produces scrap.
(2) Cut portion of sheet is Scrap.
combination dies is used.
oneration or
 Die

Pressure pad
(c)U-bending
Fig. 4.5.2 :Bending operations
4.6 Safety Practices/
Precautions in Forging and Press Shop
Operator working in forging and press shop must take
All forge shop equipment must be
important safety precautions. Some of themare as followe.
maintained in acondition which will ensure continued safe
It is a good practice that
operator always observe the safety rules prescribed for each operation
Operator must have the thorough knowledge of the machine.
Use
working of the forging machine before operating it.
extreme care when working with punchers, shears, and
impossible to stop them until the benders, because once they are activated. it ie
end of a cycle.
Allmanually operated valves and
switches must be clearly identified and they must bereadily
required. accessible when
In power operated hammers,every steamn or air hammer must have a safety cylinder head to
the rod should break or pull out of the ram. act as a cushion if

All up setters must be installed so that they remain on

their supporting foundations.
In Forging and trimming presses, When dies are being
changed or maintenance is being carried on the pres,
ensure the following
a) The power to the pressure is locked out.
b) The flywheel should be is at rest.
c) The ram should be is blocked with a
material of the appropriate strength.
DOO