Dave:

I've forgotten the exact construction you described, but I suspect you are
going to have to increase the friction between the two tubes by splitting
and clamping the outer. It sounds like the aluminum is simply too thin and
too soft to withstand that kind of torque against a small diameter fastener.

--
Crazy George
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"Dave Head" wrote in message
...
That was it. There is a 2" aluminum tube over a 1 1/4" stainless steel
"jackshaft". It's held with two 1/4" bolts. Holes thru aluminum tube were
elongated. Drilled to 3/8". Unfortunately, these aren't perfectly round,
either, since I drilled 'em with a hand drill, but I'm hoping the torque I
put
on the 3/8" bolts will crush the aluminum tube into clamping on the
stainless
steel. We'll see. If not, I can drill more holes thru that assembly
and put
more bolts in. It seemed more solid, but next big wind, I'll have a look.

Thanks again for the tip.

Dave Head

On Sun, 22 Feb 2004 14:46:54 -0600, "Crazy George"

wrote:

Dave:

From that description, I suspect you are going to find all the bolt holes
in
the tubing elongated from torque. We usually drill slightly oversize
holes
for our fasteners, but in this high stress application, the holes should
start undersize so the fasteners have to be driven in and are tight from
the
get-go. Also, it is necessary to select fasteners which do not have
threads
where they pass through the walls of the tubes. This is often the most
difficult challenge.