A neodymium magnet (also known as NdFeB, NIB or Neo magnet), the
most widely used type of rare-earth magnet, is a permanent magnet
made from an alloy of neodymium, iron and boron to form the
Nd2Fe14B tetragonal crystalline structure. neodymium magnets are
the strongest type of permanent magnet commercially available. They
have replaced other types of magnets in the many applications in
modern products that require strong permanent magnets, such as
motors in cordless tools, hard disk drives and magnetic fasteners.
Neodymium magnets are graded according to their maximum energy
product, which relates to the magnetic flux output per unit volume.
Higher values indicate stronger magnets and range from N35 up to
the grade indicate maximum operating temperatures (often the Curie
temperature), which range from M (up to 100 degrees Celsius) to EH
(200 degrees Celsius).