Steel
is
the
most
widely
used
engineering
material
.
Technically
,
though
,
this
well
-
known
____________________
of
____________________
and
____________________
is
not
as
simple
as
one
might
think
.
Steel
comes
in
a
huge
range
of
different
grades
,
each
with
different
characteristics
.
For
the
inexperienced
,
it
can
be
difficult
to
know
where
to
begin
.
A
good
place
to
start
is
with
the
two
main
types
of
steel
.
The
first
,
carbon
____________________
,
consist
of
iron
and
carbon
,
and
contain
no
significant
quantitites
of
other
metals
.
Carbon
steels
can
be
divided
into
three
main
grades
.
-
____________________
steel
is
a
low
carbon
steel
which
contains
up
ot
approximately
0'3
%
carbon
.
-
____________________
carbon
steel
contains
between
approximately
0'3%
and
0'6%
carbon
.
-
____________________
carbon
steel
contains
between
approximately
0'6%
and
1'4%
carbon
.
