Neodymium magnets, invented in the 1980s, are the strongest and most affordable type of rare-earth magnets. They are made of an alloy of neodymium, iron, and boron (Nd2Fe14B), sometimes abbreviated as NIB. Neodymium magnets are used in numerous applications requiring strong, compact permanent magnets, such as electric motors for cordless tools, hard disk drives, magnetic hold downs, and jewelry clasps.