Ferrite magnets can be wet pressed or dry pressed. Wet pressing yields better magnetic properties, but poorer physical tolerances. Generally, the powder is dry for grade 1 or 5 materials, and wet for grade 8 and higher materials. Sintering involves subjecting the material to high temperatures to fuse the pressed powder together, thus creating a solid material. Magnets produced through this process usually need to have some finish machining, otherwise surface finishes and tolerances are not acceptable.
Some manufacturers extrude instead of press wet powder slurry and then sinter the material.
This is sometimes done for arc segment shapes, where the arc cross-section is extruded in long lengths, sintered, and then cut to length. Tooling for this manufacturing process is usually very costly. However, parts produced through this process can have very intricate shapes and tight tolerances. Injection molded ferrite properties are either lower or about the same as grade 1 Ferrite. We are able to manufacture metal and other components of finished sub assemblies using our CNC machining facilities.