"DanG" wrote in message
...
On 3/21/2012 1:32 PM, Tim Wescott wrote:
On Wed, 21 Mar 2012 13:05:05 -0500, Lloyd E. Sponenburgh wrote:

Tim fired this volley in
:

If I must go with rounded corners, can I expect that there is a
standard? What is it? Is there a place I might find it on the web?


Tim,
Have you checked smallparts.com? Most big-box home improvement centers
and ACE hardware carry a good selection of aluminum angles, some with
unequal legs.

I just bought 4' of 4"x4"x1/2" aluminum channel from MSC. They carry
other sizes, but few with unequal legs.

On the MSC metal, the INSIDE corners (all) are rounded (ends of the legs
as well as the crotch), but the outside corners are all square.

4x4x1/2" should be big enough for your little TO-220 sink, yes?

I'll take a look. It really needs to be something that's commonly
available for machine shops, though, and for the entire life of the
product -- I'm going to be specifying this to the manufacturer for whom I
am designing the board; I'm sure they'd rather not have to send out a guy
to dig through the racks at Home Depot for something that might disappear
at any moment over the next ten years or so.

You should go to Hadco Metals to see what is/is not standard.

Architectural is sharp-cornered, structural is round-cornered. The heaviest
in architectural is 3x3x1/4.
If you need 4x4x1/2, AND you need a sharp corner, I don't think a machine
shop would charge too much to square the inside/outside corners of
structural.

And for what MSC/HD charge, you could get whole lengths from Hadco or other
alum suppliers.
PSC in PA will cut and ship UPS, nice people.

Btw, 4x4x1/2 is really hefty stuff. I've got 2.5x2.5x1/4 structural, and
DATS hefty!!
--
EA





You might look he
http://www.mdteam.com/index.php/prod...a-metal-sheets
Macklanburg Duncan makes these aluminum extrusions and should be readily
available through most lumber yards and box stores.

--


___________________________________

Keep the whole world singing . . .
Dan G
remove the seven