... ,wear,corrosion resitance 2.maintenance free full ceramic ball bearing of silicon nitride materia1.Full ceramic bearing made with ZrO2 have ... lubrication and maintance free when working,especiall high and low-temperature application,etc.,could be used in awful environment and ... specially condition,2.The rings and balls: full ceramic materia:ZrO23.The cage :PTFE, GFRPA66-25,PEEK, ...