It all depends on what load you are going to apply to it. In pure numbers
the Moment of inertia of a 1" solid rod is .0490874.
A tube with a .5" ID it is .0460194 so you don't loose a lot.
For a .75"ID it is .0335558 so you loose about a third
For a .875" ID it is down to .0203133 so it is less than half as stiff.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

"Ron Hubbard" wrote in message
...
Does anybody know how much you can bore out a 1" dia. 6061 aluminum rod
before it
loses it's structural integrity
and either bends or breaks?.

Ron


--
"Everybody has a secret except for me and my monkey."