Hey Rick,
There really isn't such a thing as a tough 9/32" mandrel! They will all bend or whip due to their size. I've got several custom made stub mandrels with a 10degree taper to 9/32" shaft that work great. They also have a #2MT so they are as short,stiff and as accurate as possible. These were custom CNC'd for me by a friend and would have cost several hundred $$$ to have made!
Hut sells a 7mm mandrel that has an aligning section on the thread end. It is higher precision than a standard shaft. The adjustable mandrels are probably the best because you can shorten them so they are less prone to whip or bend.
If you have any old printers laying around, check the running gear in them for 7mm or even 1/2" shafts. They are highly polished and made from high strength stainless. You will have to mount them in a collet or chuck but they work great! /ubbthreads/images/graemlins/wink.gif
Nikonut /ubbthreads/images/graemlins/grinning-smiley-003.gif