<s>
In	O
electronics	O
,	O
TO-18	O
is	O
a	O
designation	O
for	O
a	O
style	O
of	O
transistor	B-Application
metal	O
case	O
.	O
</s>
<s>
The	O
case	O
is	O
more	O
expensive	O
than	O
the	O
similarly	O
sized	O
plastic	O
TO-92	B-Algorithm
package	O
.	O
</s>
<s>
The	O
name	O
is	O
from	O
JEDEC	O
,	O
signifying	O
Transistor	B-Application
Outline	O
Package	O
,	O
Case	O
Style	O
18	O
.	O
</s>
<s>
The	O
3-lead	O
TO-18	O
is	O
used	O
for	O
transistors	B-Application
and	O
other	O
devices	O
using	O
no	O
more	O
than	O
three	O
leads	O
.	O
</s>
<s>
For	O
example	O
,	O
diode	O
lasers	O
such	O
as	O
those	O
found	O
in	O
CD	B-Device
players	I-Device
may	O
be	O
packaged	O
in	O
TO-18	O
cases	O
with	O
a	O
lens	O
.	O
</s>
<s>
TO-206	B-Algorithm
is	O
intended	O
to	O
replace	O
previous	O
definitions	O
of	O
packages	O
with	O
leads	O
arranged	O
in	O
a	O
circle	O
with	O
a	O
diameter	O
of	O
.	O
</s>
<s>
The	O
different	O
outlines	O
are	O
now	O
defined	O
as	O
variants	O
of	O
TO-206	B-Algorithm
:	O
TO-18	O
is	O
renamed	O
to	O
TO-206-AA	O
,	O
TO-46	O
to	O
TO-206-AB	O
,	O
TO-52	O
to	O
TO-206-AC	O
,	O
TO-72	O
to	O
TO-206-AF	O
.	O
</s>
<s>
smaller	O
than	O
TO-46	O
)	O
is	O
added	O
as	O
TO-206-AD	O
.	O
</s>
<s>
TO-206-AE	O
does	O
not	O
require	O
a	O
minimum	O
diameter	O
of	O
the	O
leads	O
but	O
is	O
otherwise	O
identical	O
to	O
TO-18	O
.	O
</s>
<s>
The	O
somewhat	O
unrelated	O
TO-58	O
package	O
is	O
included	O
as	O
TO-206-AG	O
.	O
</s>
