--- cut, cut, cut ------
> (Do^4 - Di^4)/Do^4 = Ratio of hollow shaft stiffness to same dia solid
>stiffness
>
> (Do^2 - Di^2)/Do^2 = Ratio of hollow shaft weight to same dia solid weight
>
>
> To compare a hollow shaft to a different dia solid, just substitute the
> solid shaft's diameter into the Do of the denominator.
>
> Aluminum is .343 times as stiff as steel and .348 times as heavy as
> steel (carbon steel).
>
> Bob Luffel (there are a lot of Bob's around here, aren't there?)
>
Yeah, but only one important "Bob" and he is the guy that keeps this server going!!
"Friendly" Bob Madden <madden@netcom.com>