The bodies of the MPI Permanent Magnets | CrackTest are annodised and are supplied with a mild steel keeper. These magnets lift the standard 18kg test block.
A rare-earth magnet is a strong permanent magnet made from alloys of rare earth elements, or lanthanide metals, with other metals. They are substantially stronger than ferrite or alnico magnets.The magnetic field produced by rare-earth magnets can be well over 1.2 teslas. By comparison, ferrite or ceramic magnets typically exhibit around 50 to 100 milliteslas. The most powerful and affordable type of rare-earth magnet is a neodymium magnet. Neodymium magnets are made of neodymium,iron and boron in the formula Nd2Fe14B.