300 series Stainless Steel

[mikeinkaty]

http://www.portlandbolt.com/faqs/18-8-304-and-316-stainless-steel/

'austenitic' stainless steels are non-magnetic.

Mike

 

[Woodworker1997]

Looks like 316 SS would be the best choice due to its chemical resistance.

Derek

 

[goldsilverpro]

For nitric acid resistance, 304 is much better than 316. 316 contains Mo and 304 doesn't and this is what makes the difference. Nitric drums are made of 304.

 

[rustbucketguy]

You are correct, goldsilverpro. In commercial nitric acid production plants the predominant grade of stainless steel is 304, with 304L (L for low carbon) for use in the wet portions, and 304H (H for high carbon) for use in dry portions, typically over 300 degrees F. In general, 316 is preferred for certain chemicals, but nitric acid is not one of them.

 

[4metals]

I had a client buy a stainless tank from a used equipment dealer who claimed it was 304 to use as a heated tank to digest silver to make electrolyte. Long story short the tank was eaten out in less than 8 months. Turned out the tank was 316.

The replacement tank was 304L and I drilled it and had it analyzed it to be sure. (The failure of the first tank wasn't just a spill recover and reprocess situation, it was a costly mess.) It's going on 2 years of dissolving silver every day and still has a shine.

 

[Jimmy]

However if you are into salts,clorides, 316 is way better than 304.
I do a lot of molten salt hardening and quenching and have my pots specially cast. Not cheap but they do last.