My dad has a HUGE magnet on his workshop.
I love magnets, and when I saw it, I asked him what it was for.
His reply was: "I don't know why, but inox steel bolts don't get attracted to it, so I use it to identify them."
Thus I got curious, why a magnet don't attract inox steel bolts? Steel, even if a inox variation is still mostly iron, no?