We all know that magnets attract each other at opposite poles and repel at like poles. But exactly what types of metals do they attract? Neodymium magnets are known as the strongest magnet material available and have the highest holding strength to these metals. They are called ferromagnetic metals containing mainly iron, nickel and rare earth alloys. On the contrary, paramagnetism is the very weak attraction between other metals and magnets for which you can barely notice.
The most commonly used metals to be attracted by magnets or magnetic devices are ferrous metals which contain iron and iron alloys. Steels, for examples, are widely applied and can be easily handled by lifting devices containing neodymium magnets. Due to the fact that these iron electrons and their magnetic fields can be easily aligned with external magnetic field, it is easy for neodymium magnets to attract to them. And based on the same theory, neodymium magnets composed of iron can be induced by powerful magnetic field and retain the magnetism. Stainless steel alloys on the other hand do not have this property and cannot be attracted to a magnet. Elemental nickel and some nickel alloys are also ferromagnetic, such as Aluminum-Cobalt-Nickel (alnico) magnets. The key for them to attract to magnets is their alloy composition or which other elements do they have. The nickel coins are not ferromagnetic because they contain majority of copper and a smaller portion of nickel.
Metals like aluminum, copper and gold show paramagnetism or weakly attractive. When placed in a magnetic field or close to a magnet, such metals create their own magnetic fields that weakly attract them to the magnet and do not persist when the external magnetic field is removed.
Thus, it is important to understand your material before purchasing any magnet material, mounting magnets or lifting magnets. It is best to find out the compositions of your metal material for which certain contents, i.e. carbon, significantly affect the magnet pull strength.
Post time: Apr-22-2020