[Platinum]

I know that boiling HCl (aq) would eat stainless steel pretty fast. Stainless steel is sometimes (often?) used in pipes where H2SO4 is present, over 90% strength. I suppose heat in the latter case is avoided. My question is how long (difficult to answer probably) time I could boil H2SO4 in a cheap stainless steel pot. Very roughly, of course - are we talking a few hours or days? 

[Hunter2]

It depends which kind of stainless steel. Some will not attacked by sulfuric, other will be corroded after some day.  Also the purity of the sulfuric is important. Avoid any Chloride, it will eat any stainless steel.