"John" wrote in message
nk.net...
I know that after machining SS the heat creates a martensitic structure
that
does not allow for magnetic alignment.

I'm having a little trouble with the idea that machining creates enough heat
to make such a change. Transformation takes place at quite high
temperature, typically red heat.

Regular carbon steel will still maintain some magnetism.

Yep, but that's not the point. One isn't checking to see if the drum is a
magnet. The inspection procedure is to determine if the drum is
*magnetic*, which would sort out steel from stainless. Dead annealed, a
steel drum is still very magnetic. A stainless drum (300 series stainless)
would not be.

Harold