Stainless steel

I have seen some posts that there are a few different types of stainless steel. There is a plumbing yard that I pick up dishwashers from, and if the outside of the door is non-magnetic stainless steel, I remove it. I have about 30 of them now that I have cleaned up, and was wondering how I figure out what type of stainless they are so I can go to my yard prepared.

Non-magnetic stainless from dishwashers will always be 304 stainless (also called 18-8) at the yard. Unless the yard has a niton gun to shoot the metal or the metal has mill marks or something else on it to indicate it it is 316, it is unusual to get 316 price even if that's what the material is.