In fact, these two magnets are both neodymium iron boron, and they are distinguished by their production process. Bonded NdFeB magnets are actually made by injection molding, while sintered NdFeB magnets are made by pumping out and heating them at high temperatures. Since bonded NdFeB magnets are injection molded, they contain adhesives and their density is generally only 80% of the theoretical amount. Sintered NdFeB magnets have gone through a complex high-temperature heating process, so in terms of magnetism, the attenuation of bonded NdFeB magnets relative to sintered NdFeB magnets is about 30%.

Sintered NdFeB magnets are anisotropic magnets produced by powder sintering. Generally, only blanks can be produced through sintering, which are then processed into magnets of various shapes through mechanical processing (such as wire cutting, slicing, grinding, etc.). Sintered NdFeB is a hard and brittle material that is difficult to process. Its process loss is large, the cost is high, the dimensional accuracy is poor, the corrosion resistance is poor, and the surface requires electroplating treatment. But the advantage is high performance, which has reached more than 50M.

Bonded NdFeB magnet, composed of Nd2Fe14B, is a synthetic magnet. Bonded NdFeB magnets are magnets made of fast-quenched NdFeB magnetic powder and binder through "compression molding" or "injection molding". Bonded NdFeB magnets have high dimensional accuracy and can be made into magnetic components with relatively complex shapes. They have the characteristics of one-time molding and multi-pole orientation. Bonded NdFeB magnets have high mechanical strength and can be formed simultaneously with other supports during molding.