<s>
Technical	B-Application
drawing	I-Application
,	O
drafting	O
or	O
drawing	O
,	O
is	O
the	O
act	O
and	O
discipline	O
of	O
composing	O
drawings	B-Application
that	O
visually	O
communicate	O
how	O
something	O
functions	O
or	O
is	O
constructed	O
.	O
</s>
<s>
Technical	B-Application
drawing	I-Application
is	O
essential	O
for	O
communicating	O
ideas	O
in	O
industry	O
and	O
engineering	O
.	O
</s>
<s>
To	O
make	O
the	O
drawings	B-Application
easier	O
to	O
understand	O
,	O
people	O
use	O
familiar	O
symbols	O
,	O
perspectives	B-Architecture
,	O
units	O
of	O
measurement	O
,	O
notation	O
systems	O
,	O
visual	O
styles	O
,	O
and	O
page	O
layout	O
.	O
</s>
<s>
Many	O
of	O
the	O
symbols	O
and	O
principles	O
of	O
technical	B-Application
drawing	I-Application
are	O
codified	O
in	O
an	O
international	O
standard	O
called	O
ISO	B-Application
128	I-Application
.	O
</s>
<s>
The	O
need	O
for	O
precise	O
communication	O
in	O
the	O
preparation	O
of	O
a	O
functional	O
document	O
distinguishes	O
technical	B-Application
drawing	I-Application
from	O
the	O
expressive	O
drawing	O
of	O
the	O
visual	O
arts	O
.	O
</s>
<s>
Artistic	O
drawings	B-Application
are	O
subjectively	O
interpreted	O
;	O
their	O
meanings	O
are	O
multiply	O
determined	O
.	O
</s>
<s>
Technical	B-Application
drawings	I-Application
are	O
understood	O
to	O
have	O
one	O
intended	O
meaning	O
.	O
</s>
<s>
A	O
professional	O
drafter	O
who	O
makes	O
technical	B-Application
drawings	I-Application
is	O
sometimes	O
called	O
a	O
drafting	O
technician	O
.	O
</s>
<s>
A	O
sliding	O
straightedge	O
known	O
as	O
a	O
T-square	B-Application
is	O
then	O
placed	O
on	O
one	O
of	O
the	O
sides	O
,	O
allowing	O
it	O
to	O
be	O
slid	O
across	O
the	O
side	O
of	O
the	O
table	O
,	O
and	O
over	O
the	O
surface	O
of	O
the	O
paper	O
.	O
</s>
<s>
"	O
Parallel	O
lines	O
"	O
can	O
be	O
drawn	O
simply	O
by	O
moving	O
the	O
T-square	B-Application
and	O
running	O
a	O
pencil	O
or	O
technical	O
pen	O
along	O
the	O
T-square	B-Application
'	O
s	O
edge	O
.	O
</s>
<s>
The	O
T-square	B-Application
is	O
used	O
to	O
hold	O
other	O
devices	O
such	O
as	O
set	O
squares	O
or	O
triangles	O
.	O
</s>
<s>
In	O
this	O
case	O
,	O
the	O
drafter	O
places	O
one	O
or	O
more	O
triangles	O
of	O
known	O
angles	O
on	O
the	O
T-square	B-Application
—	O
which	O
is	O
itself	O
at	O
right	O
angles	O
to	O
the	O
edge	O
of	O
the	O
table	O
—	O
and	O
can	O
then	O
draw	O
lines	O
at	O
any	O
chosen	O
angle	O
to	O
others	O
on	O
the	O
page	O
.	O
</s>
<s>
Modern	O
drafting	O
tables	O
come	O
equipped	O
with	O
a	O
drafting	B-Application
machine	I-Application
that	O
is	O
supported	O
on	O
both	O
sides	O
of	O
the	O
table	O
to	O
slide	O
over	O
a	O
large	O
piece	O
of	O
paper	O
.	O
</s>
<s>
In	O
addition	O
,	O
the	O
drafter	O
uses	O
several	O
technical	B-Application
drawing	I-Application
tools	I-Application
to	O
draw	O
curves	O
and	O
circles	O
.	O
</s>
<s>
A	O
common	O
error	O
is	O
to	O
allow	O
the	O
triangles	O
to	O
push	O
the	O
top	O
of	O
the	O
T-square	B-Application
down	O
slightly	O
,	O
thereby	O
throwing	O
off	O
all	O
angles	O
.	O
</s>
<s>
Even	O
tasks	O
as	O
simple	O
as	O
drawing	O
two	O
angled	O
lines	O
meeting	O
at	O
a	O
point	O
require	O
a	O
number	O
of	O
moves	O
of	O
the	O
T-square	B-Application
and	O
triangles	O
,	O
and	O
in	O
general	O
,	O
drafting	O
can	O
be	O
a	O
time-consuming	O
process	O
.	O
</s>
<s>
A	O
solution	O
to	O
these	O
problems	O
was	O
the	O
introduction	O
of	O
the	O
mechanical	O
"	O
drafting	B-Application
machine	I-Application
"	O
,	O
an	O
application	O
of	O
the	O
pantograph	O
(	O
sometimes	O
referred	O
to	O
incorrectly	O
as	O
a	O
"	O
pentagraph	O
"	O
in	O
these	O
situations	O
)	O
which	O
allowed	O
the	O
drafter	O
to	O
have	O
an	O
accurate	O
right	O
angle	O
at	O
any	O
point	O
on	O
the	O
page	O
quite	O
quickly	O
.	O
</s>
<s>
Today	O
,	O
the	O
mechanics	O
of	O
the	O
drafting	O
task	O
have	O
largely	O
been	O
automated	O
and	O
accelerated	O
through	O
the	O
use	O
of	O
computer-aided	B-Application
design	I-Application
systems	O
(	O
CAD	B-Application
)	O
.	O
</s>
<s>
There	O
are	O
two	O
types	O
of	O
computer-aided	B-Application
design	I-Application
systems	O
used	O
for	O
the	O
production	O
of	O
technical	B-Application
drawings	I-Application
:	O
two	O
dimensions	O
(	O
"	O
2D	O
"	O
)	O
and	O
three	O
dimensions	O
(	O
"	O
3D	O
"	O
)	O
.	O
</s>
<s>
2D	O
CAD	B-Application
systems	O
such	O
as	O
AutoCAD	B-Algorithm
or	O
MicroStation	B-Algorithm
replace	O
the	O
paper	O
drawing	O
discipline	O
.	O
</s>
<s>
It	O
is	O
down	O
to	O
the	O
technical	B-Application
drawing	I-Application
skill	O
of	O
the	O
user	O
to	O
produce	O
the	O
drawing	O
.	O
</s>
<s>
There	O
is	O
still	O
much	O
scope	O
for	O
error	O
in	O
the	O
drawing	O
when	O
producing	O
first	O
and	O
third	O
angle	O
orthographic	O
projections	O
,	O
auxiliary	O
projections	O
and	O
cross-section	B-Application
views	O
.	O
</s>
<s>
A	O
2D	O
CAD	B-Application
system	O
is	O
merely	O
an	O
electronic	O
drawing	O
board	O
.	O
</s>
<s>
Its	O
greatest	O
strength	O
over	O
direct	O
to	O
paper	O
technical	B-Application
drawing	I-Application
is	O
in	O
the	O
making	O
of	O
revisions	O
.	O
</s>
<s>
Whereas	O
in	O
a	O
conventional	O
hand	O
drawn	O
technical	B-Application
drawing	I-Application
,	O
if	O
a	O
mistake	O
is	O
found	O
,	O
or	O
a	O
modification	O
is	O
required	O
,	O
a	O
new	O
drawing	O
must	O
be	O
made	O
from	O
scratch	O
,	O
the	O
2D	O
CAD	B-Application
system	O
allows	O
a	O
copy	O
of	O
the	O
original	O
to	O
be	O
modified	O
,	O
saving	O
considerable	O
time	O
.	O
</s>
<s>
2D	O
CAD	B-Application
systems	O
can	O
be	O
used	O
to	O
create	O
plans	O
for	O
large	O
projects	O
such	O
as	O
buildings	O
and	O
aircraft	O
but	O
provide	O
no	O
way	O
to	O
check	O
the	O
various	O
components	O
will	O
fit	O
together	O
.	O
</s>
<s>
A	O
3D	O
CAD	B-Application
system	O
(	O
such	O
as	O
KeyCreator	B-Algorithm
,	O
Autodesk	B-Device
Inventor	I-Device
,	O
or	O
SolidWorks	B-Application
)	O
first	O
produces	O
the	O
geometry	O
of	O
the	O
part	O
;	O
the	O
technical	B-Application
drawing	I-Application
comes	O
from	O
user	O
defined	O
views	O
of	O
that	O
geometry	O
.	O
</s>
<s>
The	O
main	O
scope	O
for	O
error	O
comes	O
in	O
setting	O
the	O
parameter	O
of	O
first	O
or	O
third	O
angle	O
projection	O
and	O
displaying	O
the	O
relevant	O
symbol	O
on	O
the	O
technical	B-Application
drawing	I-Application
.	O
</s>
<s>
3D	O
CAD	B-Application
allows	O
individual	O
parts	O
to	O
be	O
assembled	O
together	O
to	O
represent	O
the	O
final	O
product	O
.	O
</s>
<s>
Buildings	O
,	O
aircraft	O
,	O
ships	O
,	O
and	O
cars	O
are	O
modeled	O
,	O
assembled	O
,	O
and	O
checked	O
in	O
3D	O
before	O
technical	B-Application
drawings	I-Application
are	O
released	O
for	O
manufacture	O
.	O
</s>
<s>
Both	O
2D	O
and	O
3D	O
CAD	B-Application
systems	O
can	O
be	O
used	O
to	O
produce	O
technical	B-Application
drawings	I-Application
for	O
any	O
discipline	O
.	O
</s>
<s>
BS	O
and	O
ISO	B-General_Concept
produce	O
standards	O
to	O
show	O
recommended	O
practices	O
but	O
it	O
is	O
up	O
to	O
individuals	O
to	O
produce	O
the	O
drawings	B-Application
to	O
a	O
standard	O
.	O
</s>
<s>
The	O
only	O
standard	O
across	O
engineering	O
workshop	O
drawings	B-Application
is	O
in	O
the	O
creation	O
of	O
orthographic	O
projections	O
and	O
cross-section	B-Application
views	O
.	O
</s>
<s>
In	O
representing	O
complex	O
,	O
three-dimensional	O
objects	O
in	O
two-dimensional	O
drawings	B-Application
,	O
the	O
objects	O
can	O
be	O
described	O
by	O
at	O
least	O
one	O
view	O
plus	O
material	O
thickness	O
note	O
,	O
2	O
,	O
3	O
or	O
as	O
many	O
views	O
and	O
sections	O
that	O
are	O
required	O
to	O
show	O
all	O
features	O
of	O
object	O
.	O
</s>
<s>
To	O
communicate	O
all	O
aspects	O
of	O
the	O
shape	O
or	O
design	O
,	O
detail	O
drawings	B-Application
are	O
used	O
.	O
</s>
<s>
In	O
this	O
field	O
,	O
the	O
term	O
plan	B-Application
is	O
often	O
used	O
when	O
referring	O
to	O
the	O
full	O
section	B-Application
view	O
of	O
these	O
drawings	B-Application
as	O
viewed	O
from	O
three	O
feet	O
above	O
finished	O
floor	O
to	O
show	O
the	O
locations	O
of	O
doorways	O
,	O
windows	O
,	O
stairwells	O
,	O
etc	O
.	O
</s>
<s>
Architectural	B-Architecture
drawings	I-Architecture
describe	O
and	O
document	O
an	O
architect	O
's	O
design	O
.	O
</s>
<s>
Because	O
this	O
could	O
apply	O
to	O
everything	O
that	O
humans	O
create	O
,	O
it	O
is	O
given	O
a	O
narrower	O
definition	O
in	O
the	O
context	O
of	O
technical	B-Application
drawing	I-Application
.	O
</s>
<s>
Engineering	B-Architecture
drawings	I-Architecture
generally	O
deal	O
with	O
mechanical	O
engineered	O
items	O
,	O
such	O
as	O
manufactured	O
parts	O
and	O
equipment	O
.	O
</s>
<s>
Engineering	B-Architecture
drawings	I-Architecture
are	O
usually	O
created	O
in	O
accordance	O
with	O
standardized	O
conventions	O
for	O
layout	O
,	O
nomenclature	O
,	O
interpretation	O
,	O
appearance	O
(	O
such	O
as	O
typefaces	O
and	O
line	O
styles	O
)	O
,	O
size	O
,	O
etc	O
.	O
</s>
<s>
The	O
end	O
goal	O
of	O
an	O
engineering	B-Architecture
drawing	I-Architecture
is	O
to	O
convey	O
all	O
the	O
required	O
information	O
that	O
will	O
allow	O
a	O
manufacturer	O
to	O
produce	O
that	O
component	O
.	O
</s>
<s>
Software	B-General_Concept
engineering	I-General_Concept
practitioners	O
make	O
use	O
of	O
diagrams	O
for	O
designing	O
software	O
.	O
</s>
<s>
Formal	O
standards	O
and	O
modeling	B-Language
languages	I-Language
such	O
as	O
Unified	B-Language
Modeling	I-Language
Language	I-Language
(	O
UML	B-Language
)	O
exist	O
but	O
most	O
diagramming	O
happens	O
using	O
informal	O
ad	O
hoc	O
diagrams	O
that	O
illustrate	O
a	O
conceptual	B-Application
model	I-Application
.	O
</s>
<s>
Technical	B-Application
illustration	I-Application
is	O
the	O
use	O
of	O
illustration	B-Application
to	O
visually	O
communicate	O
information	O
of	O
a	O
technical	O
nature	O
.	O
</s>
<s>
Technical	B-Application
illustrations	I-Application
can	O
be	O
component	O
technical	B-Application
drawings	I-Application
or	O
diagrams	O
.	O
</s>
<s>
The	O
aim	O
of	O
technical	B-Application
illustration	I-Application
is	O
"	O
to	O
generate	O
expressive	O
images	O
that	O
effectively	O
convey	O
certain	O
information	O
via	O
the	O
visual	O
channel	O
to	O
the	O
human	O
observer	O
"	O
.	O
</s>
<s>
The	O
main	O
purpose	O
of	O
technical	B-Application
illustration	I-Application
is	O
to	O
describe	O
or	O
explain	O
these	O
items	O
to	O
a	O
more	O
or	O
less	O
nontechnical	O
audience	O
.	O
</s>
<s>
A	O
cutaway	B-Application
drawing	I-Application
is	O
a	O
technical	B-Application
illustration	I-Application
,	O
in	O
which	O
part	O
of	O
the	O
surface	O
of	O
a	O
three-dimensional	O
model	O
is	O
removed	O
in	O
order	O
to	O
show	O
some	O
of	O
the	O
model	O
's	O
interior	O
in	O
relation	O
to	O
its	O
exterior	O
.	O
</s>
<s>
The	O
purpose	O
of	O
a	O
cutaway	B-Application
drawing	I-Application
is	O
to	O
"	O
allow	O
the	O
viewer	O
to	O
have	O
a	O
look	O
into	O
an	O
otherwise	O
solid	O
opaque	O
object	O
.	O
</s>
<s>
Cutaway	B-Application
illustrations	I-Application
avoid	O
ambiguities	O
with	O
respect	O
to	O
spatial	O
ordering	O
,	O
provide	O
a	O
sharp	O
contrast	O
between	O
foreground	O
and	O
background	O
objects	O
,	O
and	O
facilitate	O
a	O
good	O
understanding	O
of	O
spatial	O
ordering	O
"	O
.	O
</s>
<s>
The	O
two	O
types	O
of	O
technical	B-Application
drawings	I-Application
are	O
based	O
on	O
graphical	B-Algorithm
projection	I-Algorithm
.	O
</s>
<s>
While	O
multiview	O
relates	O
to	O
external	O
surfaces	O
of	O
an	O
object	O
,	O
section	B-Application
views	O
show	O
an	O
imaginary	O
plane	O
cut	O
through	O
an	O
object	O
.	O
</s>
<s>
An	O
exploded-view	B-Application
drawing	I-Application
is	O
a	O
technical	B-Application
drawing	I-Application
of	O
an	O
object	O
that	O
shows	O
the	O
relationship	O
or	O
order	O
of	O
assembly	O
of	O
the	O
various	O
parts	O
.	O
</s>
<s>
An	O
exploded	B-Application
view	I-Application
drawing	I-Application
(	O
EVD	O
)	O
can	O
show	O
the	O
intended	O
assembly	O
of	O
mechanical	O
or	O
other	O
parts	O
.	O
</s>
<s>
The	O
drawing	O
must	O
show	O
every	O
feature	O
of	O
the	O
invention	O
specified	B-Application
in	O
the	O
claims	O
and	O
is	O
required	O
by	O
the	O
patent	O
office	O
rules	O
to	O
be	O
in	O
a	O
particular	O
form	O
.	O
</s>
<s>
The	O
reason	O
for	O
specifying	O
the	O
standards	O
in	O
detail	O
is	O
that	O
the	O
drawings	B-Application
are	O
printed	O
and	O
published	O
in	O
a	O
uniform	O
style	O
when	O
the	O
patent	O
issues	O
and	O
the	O
drawings	B-Application
must	O
also	O
be	O
such	O
that	O
they	O
can	O
be	O
readily	O
understood	O
by	O
persons	O
using	O
the	O
patent	O
descriptions	O
.	O
</s>
<s>
Working	B-Application
drawings	I-Application
are	O
the	O
set	O
of	O
technical	B-Application
drawings	I-Application
used	O
during	O
the	O
manufacturing	O
phase	O
of	O
a	O
product	O
.	O
</s>
<s>
In	O
architecture	O
,	O
these	O
include	O
civil	B-Application
drawings	I-Application
,	O
architectural	B-Architecture
drawings	I-Architecture
,	O
structural	B-Application
drawings	I-Application
,	O
mechanical	B-Application
systems	I-Application
drawings	I-Application
,	O
electrical	O
drawings	B-Application
,	O
and	O
plumbing	B-Application
drawings	I-Application
.	O
</s>
<s>
Assembly	O
drawings	B-Application
show	O
how	O
different	O
parts	O
go	O
together	O
,	O
identify	O
those	O
parts	O
by	O
number	O
,	O
and	O
have	O
a	O
parts	O
list	O
,	O
often	O
referred	O
to	O
as	O
a	O
bill	O
of	O
materials	O
.	O
</s>
<s>
In	O
a	O
technical	O
service	O
manual	O
,	O
this	O
type	O
of	O
drawing	O
may	O
be	O
referred	O
to	O
as	O
an	O
exploded	B-Application
view	I-Application
drawing	I-Application
or	O
diagram	O
.	O
</s>
<s>
Also	O
called	O
As-Built	O
drawings	B-Application
or	O
As-made	O
drawings	B-Application
.	O
</s>
<s>
As-fitted	O
drawings	B-Application
represent	O
a	O
record	O
of	O
the	O
completed	O
works	O
,	O
literally	O
'	O
as	O
fitted	O
 '	O
.	O
</s>
<s>
These	O
are	O
based	O
upon	O
the	O
working	B-Application
drawings	I-Application
and	O
updated	O
to	O
reflect	O
any	O
changes	O
or	O
alterations	O
undertaken	O
during	O
construction	O
or	O
manufacture	O
.	O
</s>
