I picked up two bars of 303 stainless a little while back (3/4" and 7/8"), and just got to use them in the last couple of days.
Either they sent me two different steels, or something's odd.....I turned down some parts from both and cleaned the parts completely, then I placed them in an autoclave (steam sterilizer) for thirty minutes....when I took the two parts out, one was spotless, and one was covered with black and brownish spots.
Needless to say I wasn't able to use the crappy one.
Any ideas?, they both worked tough like stainless usually does on my machines, so I don't think one of them was anything like mild steel.
Thanks for your time and help.