As far as exhaust and grills go, if a magnet sticks to it, it probably meets the bear minimum standards to be called stainless. Non magnetic stainless usually has a high amount of nickle and/or chromium and is going to be too expensive to make an exhaust out of. (my opinion)
I have a brand new Walker stainless steel Y pipe and a magnet sticks to it. (there are rusts spots on it) I just went out side and used a magnet on my expensive(at least for me) stainless gas grill. Very interesting results. The hood and top of the grill have a slight magnetism, but the sides are highly magnetic. The handle on the hood is not magnetic at all. The sides that are highly magnetic are slightly rusting. The parts that are only slightly magnetic have no signs of corrosion after two years of being in the weather.
Just FYI, I used a very strong rare earth mangnet that I bought years ago.
Until very recently (yesterday), I though all stainless was non-magnetic
I have a brand new Walker stainless steel Y pipe and a magnet sticks to it. (there are rusts spots on it) I just went out side and used a magnet on my expensive(at least for me) stainless gas grill. Very interesting results. The hood and top of the grill have a slight magnetism, but the sides are highly magnetic. The handle on the hood is not magnetic at all. The sides that are highly magnetic are slightly rusting. The parts that are only slightly magnetic have no signs of corrosion after two years of being in the weather.
Just FYI, I used a very strong rare earth mangnet that I bought years ago.
Until very recently (yesterday), I though all stainless was non-magnetic