<s>
A	O
T-square	B-Application
is	O
a	O
technical	B-Application
drawing	I-Application
instrument	O
used	O
by	O
draftsmen	B-Application
primarily	O
as	O
a	O
guide	O
for	O
drawing	B-Application
horizontal	O
lines	O
on	O
a	O
drafting	O
table	O
.	O
</s>
<s>
T-squares	B-Application
are	O
available	O
in	O
a	O
range	O
of	O
sizes	O
,	O
with	O
common	O
lengths	O
being	O
,	O
,	O
,	O
and	O
.	O
</s>
<s>
In	O
addition	O
to	O
drawing	B-Application
horizontal	O
lines	O
,	O
a	O
T-square	B-Application
can	O
also	O
be	O
used	O
with	O
a	O
set	O
square	O
to	O
draw	O
vertical	O
or	O
diagonal	O
lines	O
.	O
</s>
<s>
The	O
T-square	B-Application
usually	O
has	O
a	O
transparent	O
edge	O
made	O
of	O
plastic	O
which	O
should	O
be	O
free	O
of	O
nicks	O
and	O
cracks	O
in	O
order	O
to	O
provide	O
smooth	O
,	O
straight	O
lines	O
.	O
</s>
<s>
T-squares	B-Application
are	O
also	O
used	O
in	O
other	O
industries	O
,	O
such	O
as	O
construction	O
.	O
</s>
<s>
For	O
example	O
,	O
drywall	O
T-squares	B-Application
are	O
typically	O
made	O
of	O
aluminum	O
and	O
have	O
a	O
long	O
tongue	O
,	O
allowing	O
them	O
to	O
be	O
used	O
for	O
measuring	O
and	O
cutting	O
drywall	O
.	O
</s>
<s>
In	O
woodworking	O
,	O
higher-end	O
table	O
saws	O
often	O
have	O
T-square	B-Application
fences	O
attached	O
to	O
a	O
rail	O
on	O
the	O
front	O
side	O
of	O
the	O
table	O
,	O
providing	O
improved	O
accuracy	O
and	O
precision	O
when	O
cutting	O
wood	O
.	O
</s>
