Ferrite is one of the most widely used permanent magnet materials. It is made by powder metallurgy. It is mainly divided into barium (Ba) and strontium (Sr), and divided into anisotropy and isotropy. It is a kind of permanent magnet material which is not easy to demagnetize and easy to corrode. Its maximum working temperature can reach 250 degrees Celsius. It is hard and brittle, and diamond sand can be used. Tool cutting, one-time forming with alloy rigid processing die. These products are widely used in the fields of permanent magnet motors and Speakers.。