Due to different manufacturing methods and use requirements, NdFeB permanent magnets can be divided into three categories:

1, injection NdFeB (Zhusu NdFeB) : with high accuracy, it is easy to make thin wall rings or thin magnets with complex anisotropic shapes.

2, Sintered NdFeB (Sintered NdFeB) : Sintered NdFeB permanent magnet is made by powder metallurgy, the main process is: alloying (melting) → rough crushing → fine crushing → grinding into 3 ~ 5.0µm fine powder → magnetic field orientation pressing → vacuum sintering tempering → inspection → processing → finished product.

3. Bonded NdFeB (Bonded NdFeB) : NdFeB bonded magnets are used to obtain microcrystalline powders by chilling method, each powder contains a number of Nd-Fe-B microcrystalline grains, and then the powder is mixed and bonded with polymers or other binders, then pressed, extruded or calendered to form a plastic permanent magnet, so the usual NdFeB bonded magnets are non-dense isotropic magnets.

Generally, the magnetic properties of NdFeB bonded magnets are much lower than NdFeB sintered magnets, but NdFeB bonded magnets have many irreplaceable advantages of NdFeB sintered magnets: high machining accuracy, high yield, high precision, excellent magnetic properties, good corrosion resistance, and good temperature stability; In addition, the Nd-Fe-B bonded magnet is also easy to magnetize in any direction, and can be easily made of multi-pole or even countless pole integral magnets.