1, according to the different materials, different forming methods, such as ferrite powder metallurgy method is used, aluminum nickel and cobalt are two kinds of casting and powder metallurgy; samarium cobalt, neodymium iron boron powder metallurgy are used. Injection molding plastic is; rubber is rolling and extrusion using two.
2, according to different uses, the speed of magnetic force by magnetic vary. Of course, also reduce the magnetic speed magnetic material itself is closely related to security, some designs use 10, some 20 years even if no obvious decay, basically a magnet and iron if shared, the formation of magnetic loops are more difficult to reduce the magnetic.