Normal steel vs. Magnetic stainless

Basically, by the rust. If there is rust, it's "normal" steel. If no rust and you still wonder, try this: Use grinder on a piece of steel to rough it up and make sure it's not chrome-plated; then get the piece of metal wet. Let sit over night. If there is any discoloration, it's in the process of forming rust. As an added factor, before leaving it sit overnight, protect a section from the air/moisture by putting scotch tape on it. Next morning, pull off the scotch tape and look for any difference in the protected area.

Didn't think of the rust. Thanks

Stainless steel in metallurgical definition is steel that contains 14% or more chromium. Other alloying elements such as nickel ca also improve steel’s resistance properties. The amount of free chromium, i.e. not tied up in carbides determines steel’s stain resistance ability. Higher carbon content leaves less free chromium in the alloy, which explains why some of the high and stainless steels with more percent of chromium are less stain resistant than lower grade stainless steels with less chromium and carbon. However, given time and conditions all steels will rust.