Metal
Cutting
During stone age, mechanical methods were first adopted for material removal. The materials could be shaped by a chipping process.
As
early
as
4000
B.
C.,
the
Egyptians
used
a
rotating
bowstring
device
to
drill
holes
in
stones.
Scientific
work
in
metal
cutting
is
of
rather
recent
origin
beginning
about
the
mid-nineteenth
century
The
early
metal
cutting
work
was
mainly
directed
toward
measuring
the
work
required
to
remove
a
given
volume
of
material
in
drilling.
The
first
attempts
to
explain
how
chips
(i.e.,
the
shavings
or
sway
removed
during
the
cutting
of
metal)
are
formed
were
made
by
Time
in
1870
and
Tresca
in
1873.
In
1881,
Mallock
suggested
correctly
that
the
metal
cutting
process
was
basically
one
of
shearing
the
work
material
to
form
the
chip
and
emphasized
the
importance
of
the
effect
of
friction
on
the
cutting
tool
face
as
the
chip
was
removed.
In
addition
he
observed
the
effect
of
cutting
lubricants.
Many
of
his
observations
are
surprisingly
close
to
the
accepted
modern
theories
and
are
still
being
repeated
100
years
later.
In
1906
Taylor
investigated
the
effect
of
tool
material
and
cutting
conditions
on
tool
life
during
roughing
operations.
One
fundamental
discovery
made
by
Taylor
was
that
the
temperature
existing
at
the
tool
cutting
edge
controlled
the
tool-wear
rate.
In
1941,
Ernst
and
Merchant
published
their
paper
dealing
with
the
mechanics
of
metal
cutting.
Metal
cutting
commonly
called
machining
produces
a
desired
shape,
size
and
finish
on
a
rough
block
of
work
piece
material
with
the
help
of
a
wedge
shaped
tool
that
is
constrained
to
move
relative
to
the
work
piece
in
such
a
way
that
a
layer
of
metal
is
removed
in
the
form
of
a
chip
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