Relatively low cost ; poor resistance to corrosion and should have a coating ; Very high strength; can replace SmCo magnets Sintered neodymium-iron-boron (Nd-Fe-B) magnets are the most powerful commercialized permanent magnets available today, with maximum energy product ranging from 35 MGOe to 52 MGOe. Nd-Fe-B is the third generation of permanent magnet developed in the 1980s. It has a ...