source for aluminum tubing with rounded corners?

Kyler Laird writes:

I've been ordering a bunch of round tubing from Aircraft Spruce
but the only square tubing they advertise has sharp corners. I
need some 1" square tubing with rounded corners. The specs.
are not critical beyond that; I'll try to work with what's
available.

I ordered some tubing from 80/20 Inc.
http://www.8020.net/
Later I found that a new hardware store in town carries it too.

It *almost* works but I realized that I need something that is
just slightly smaller. I'm not sure if I need a fractional size
or simply a 25mm tube. I'm working on that today.

Either way, I doubt that I'll be able to find small quantities
of such tubing. I've been calling and no one seems to stock it.

'looks like I might have to get a sheet metal brake and bend my
own tube (and then weld it with my spiffy new Precision TIG).

--kyler