The magnets are composed of neodymium, iron, boron and a few transition metals. Sintered ndfeb magnets are the most powerful permanent magnets available today. It has a combination of very high remanence and coercivity, and comes with a wide range of grades, sizes and shapes such as rings, blocks, discs and segments. With its excellent magnetic characteristics and abundant raw material, ndfeb magnet offers more flexibility in designing of new or replace the traditional magnet materials such as ferrite, alnico and sm-co to achieve high efficiency, low cost and more compact devices. Ndfeb magnet is highly susceptible to corrosion and coating is always necessary. Frequently they are plated in nickel, zinc, tin and epoxy resin.