Brand bonded magnets (injection molded, compression bonded, and flexible) represent one of the more important groups of magnetic materials available today. They can be tailored to suit a wide range of magnetic and physical strength, size, shape, and temperature characteristics. Compression bonded magnets are well-suited where maximum magnetic strength is required but physical strength can be slightly compromised, and where the profile shape is not complex. Another advantage over injection molded magnets is that tooling costs are relatively low making compression bonded a better choice than injection where volumes are low. With relatively little automation, compression bonded also lends itself well to high volume manufacturing (millions of magnets per year).

Magnetic powders appropriate for compaction pressing include the many neodymium-iron-boron (NdFeB) grades as well as crushed and powdered samarium cobalt (SmCo). Ferrite is not useful due to the ultra-fine particle size. Combinations of NdFeB grades may also be used to create a specific set of magnetic characteristics.

The NdFeB materials used in this process are isotropic materials which do not require magnetic alignment of the powder during processing. The pressed product is extremely uniform in all directions. Uniformity of final magnetization is totally a function of the magnetizing equipment.

Almost all manufacturers use an epoxy binder. Various other additives are used to improve adhesion to the magnetic powder, corrosion resistance, flowability for improved die-fill, etc. The epoxies are quite resistant to solvents, but may suffer some softening and swelling if exposed for more than a short time. There is also considerable open porosity. To reduce corrosion of the rare earth materials, it may be necessary to apply a coating to the magnet.