"Ed Huntress" wrote in message ...
On Thu, 22 Mar 2012 07:39:06 -0700, "PrecisionmachinisT"
wrote:


wrote in message
. ..
On Thu, 22 Mar 2012 04:29:43 -0700 (PDT), "
wrote:

On Mar 21, 9:07 pm, wrote:


When I've needed sharp cornered aluminum angle in the past I've
ordered "architectural" angle. It looks like you may need to order 2x2
in order to get the 1/4 thickness. And the alloy is 6063T52. If I was
cutting the angle shorter I would probably use a 3" dia. slotting saw
blade in the mill and spin it really fast. That would leave a good
finish, be accurate, and be fast.
Eric

Before deciding on the size, it would be worthwhile to consider the
alloy. I may not remember correctly, but I think 1100 would be
cheaper and also conduct heat much better. So it might be cheaper and
better to use angle with a rounded edge.

Dan
But machining 1100 is more expensive than 6061 or 6063 because it's so
soft.
Eric

Pretty sure 1100 isn't supplied in extruded shapes excepting for square,
round and rectangular.

You mentioned 6063. That's the standard extrustion alloy for heat
sinks. Conductivity is around 200 W/m-K in low tempers. For
comparison, 1199-O or 1100 is in the neighborhood of 240.

Extrusion dies are so cheap to make these days that extrusion jobbers
often accumulate large numbers of them, and offer standard extruded
shapes, including simple angles and elaborate finned heat sinks, as
off-the-shelf stock items. If you need a lot, you can get quite short
runs on a jobbing basis.

Then you just bandsaw them to length. That's standard practice.

The reason dies are so cheap to make is that they're easy wirecut EDM
work. They cut the die shape and the taper in one pass.


Last time I bought custom extrusion pretty sure the minimum run was 2000lbs, but that was at least 10 years ago.