Neodymium magnets are the most widely used rare-earth magnet, made from an alloy of neodymium, iron and boron. It was developed independently in 1982 by General Motors who partnered with Sumitomo Special Metals, and these neodymium magnets are the strongest type of permanent magnet commercially available. Since their introduction, they’ve replaced other types of magnets in modern products, like motors in cordless tools, hard disk drives and magnetic fasteners.