A
____________________
operation
is
one
in
which
the
shape
of
a
metal
sample
is
altered
by
____________________
deformation
.
Forming
processes
include
stamping
,
rolling
,
extrusion
and
forging
.
Forming
can
be
divided
into
two
categories
:
hot
and
cold
working
.
Deformation
energy
requirements
for
____________________
working
are
less
than
that
of
____________________
working
.
In
a
____________________
operation
,
a
single
piece
of
metal
,
normally
hot
,
is
deformed
mechanically
by
the
application
of
successive
blows
or
by
continuous
squeezing
.
Rolling
is
the
most
widely
used
deformation
process
.
It
consists
of
passing
metal
between
two
rollers
,
which
exert
compressive
stresses
,
reducing
the
metal
thickness
.
____________________
is
the
pulling
of
a
metal
piece
through
a
die
by
means
of
a
tensile
force
applied
to
the
exit
side
.
A
reduction
in
cross
-
sectional
area
results
,
with
a
corresponding
increase
in
length
.
Metals
can
be
formed
to
much
closer
dimensions
by
____________________
than
by
____________________
.
For
____________________
drawing
,
the
starting
sheet
of
metal
is
larger
than
the
area
of
the
punch
.
A
pressure
plate
,
fixed
to
the
machine
,
prevents
wrinkling
of
the
edges
as
the
plug
is
drawn
into
a
top
die
cavity
.
The
outer
parts
of
the
sheet
are
drawn
in
towards
the
die
as
the
operation
proceeds
.
In
____________________
,
a
bar
or
metal
is
forced
from
an
enclosed
cavity
via
a
die
orifice
by
a
compressive
force
applied
by
a
ram
.
