There are three name schemes for the grade of ferrite magnet: United States Industry Standard, International Electrotechnical Commission Standard, and Chinese Standard. International Electrotechnical Commission Standard is basically confined to European. The grade is made up of the simplification of the minimum value of the energy product in SI unit “kJ/m3” and intrinsic coercivity in SI unit “kA/m”. For United States Standard, grade of ferrite magnets is commonly labelled with the letter “C” and a number, such as the best-known C5 grade or C8 grade.
Since most production of ferrite magnets is in China, Chinese nomenclature system has taken over the naming right of grade. The grade beginning with the letter “Y” is the acronym for permanent magnet in Chinese phonetic alphabet. The number following it represent the nominal value of energy product and any letter after the number is the serial number.
