Three problems - - - - -

"Welded", not seamless
"Annealed"- - - - -"soft"
"Stainless"- - - - -no idea if it can be heat treated to the proper hardness.

Few poeple I know of, except maybe a particularly obnoxious machinist, have the right type of heat treat facilities to harden a fabricated shaft properly to work with needle bearings running on them.

Other than that- - - - -good idea!
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!