|What do some permanent-magnet generators have stainless-steel axles? — RC, Port-au-Prince, Haiti
Many forms of stainless steel, including those designated as "18-8 stainless," are completely non-magnetic. In contrast to normal steel, which has a microscopic magnetic structure and is easily magnetized by a strong magnetic field, these non-magnetic stainless steels are entirely free of magnetic structure. They cannot be magnetized, even temporarily. In machinery that contains strong permanent magnets, using non-magnetic stainless steel for the mechanical parts avoids undesirable attractions between parts and distortions of the required magnetic fields. While copper, aluminum, or brass could also be used—they are non-magnetic as well—stainless steels are generally much tougher metals.