Karl,
If you weld Chrome-moly, it must be annealed and then heat treated correctly
or you will end up with stress risers and embrittelment at the welds. I
don't think aluminum in any grade can cut it there. Please also keep in mind
that Alu will fatigue and fail eventually, especially when stressed.
Steve

"Karl Townsend" wrote in message
news
Our plan B is chrome moly thinwall tubing with welded in plugs to cut the
threads for the ball joints. needs to be at least 3/4 tubing cause the
ball
joint thread is 1/2x 20.

He's thinking solid AL 3/4" round is stronger/lighter than a steel
weldament. Wrong? No way does he want a solid 3/4 steel shaft. We couldn't
find 3/4 OD 3/8 ID steel shaft, plus its almost as heavy as solid.


The one that breaks uses 3/8x18 balljoint threads and 5/8 steel OD
thickwall
tubing. The ball joint threaded shaft breaks off.


Karl


"Steve Lusardi" wrote in message
...
Bad idea Karl. The load and shock clearly identifies steel as the
lightest
choice. It may be possible to reduce weight a few grams by using a
crhome,