I have three 5 gal. corny kegs.
My first I bought from a neighbor that got out of home brewing 8 years ago. It has Pepsi Cola Btlg Co stamped in the side.
The second is a new keg I bought from AIH. Made in China IIRC.
The third is a slimline Torpedo keg from Morebeer. I think USA mfg. It has 304 stainless steel printed on the side.
I recently received some Ball and Keg magnetic level indicators and while checking them out on the Torpedo keg I noticed that the ball (with a magnet in it) wanted to stick to the bottom. So I used the capture magnet to check and found that the side was non-magnetic but the top and bottom formings were slightly magnetic. Same for the AIH keg. But the Pepsico keg was all non-magnetic.
I've always thought that 18-8 stainless steels (302, 304, 316) were non-magnetic. So, here's the question for any metals expert out there...are these ends not 304 SS? Or does the stresses of forming or machining make them partially magnetic?
And the follow-up question...if it's not the "good" SS, could iron ions get into the beer?