Well, at the risk of introducing some "big words" and causing some to rush to the dictionary (or a handy metallurgical reference
) there are three basic classifications of stainless steel based upon crystalline structure: Austentetic, Ferritic, and Martensitic. There are those big words, sorry!
Most stainless we know of, with grades such as 304, 305, 316, or 18/8, 18/10 or what have you, are all in the Austentetic class and are generally not magnetic. I say "generally" because there are some uncommon sub-classes that might exhibit slight magnetic attraction. The last two classifications are magnetic.
They all have different corrosion properties; magnetic properties, machinability, hardness, etc. are are chosen by application. For example, if a fabricated product is to be welded, one might choose a low-carbon stainless. If it were for marine use, another. If a certain post fabrication processing were required, yet another. I bought a
lot of stainless steel products and fasteners when I was in the car wash industry, and nearly everything was 304 grade; some more expensive stuff was 316. The other grades were not part of fabricated products I encountered.
William has the best low-tech way of telling: weight. The plain steel ones are heavier. Also, to me chrome has a yellowier appearance than SS, so side by side I can usually tell them apart just by color.
