On Tue, 7 Oct 2008 03:38:34 -0700 (PDT), Jim Wilkins
wrote:

On Oct 6, 11:50Â*pm, John Doe wrote:
Planning to use a short piece (2 or 3 inches) of 5/8" outer diameter
aluminum tubing. The wall thickness will be 1/16" to 1/8".

Pressing down on the center of the tube will be a maximum momentary
pressure of very roughly 300 pounds (a wild guess).

Is there any difference between 6061 aluminum and aircraft grade
aluminum for that purpose?

General ideas about the differences between the two would also be
appreciated.

"Aircraft Grade" sounds better than "beercan grade".

The poles for my extremely light Stephenson tent http://
www.warmlite.com/start.htm are 7001(?) aluminum tube, 5/8" OD,
0.015" wall. (Jack was once an aerospace engineer.) I picked the tent
up at his house and he showed me how strong the poles are by placing a
16" piece on blocks and having me stand in the middle, barefoot. OTOH
the alloy cracks easily and is 'notch sensitive'. I split the end of
one of the sections by tying it down a little too tightly on my
motorcycle with bungee cords. The tent still stands with one taped
break but it loses some wind resistance. While I was there he got a
call from someone camped on top of Mt Washington whose tent was
surviving a 125 MPH wind.

As I understand it, 6061 is the strongest alloy that doesn't have
corrosion, brittleness and joining issues requiring extra engineering
analysis.

Jim Wilkins


I would concur with your understanding. And it is WELDABLE as well.
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