... silicon nitride ball of mix ceramic ball bearing has low density, high hardness, low coefficient of friction, there is no magnetic electricity ... high-speed, high precision and long life of the hybrid ceramic ball bearing roller. Generally enclose and adopt the bearing steel ... (GCr15) or stainless steel (ALSI 440C, 316,304), the ceramic ball can select ZrO2, Si3N4 or SiC material for using ...