... is Si3N4 3.full ceramic bearing 4.we are manufacturer Si3N4Usage:bearings balls for high precision,high speed,vacuum,fixed anode X ... temp,low temp,electric insulation,high precision ballscrew set,valve balls for acid,alkali,salt,measure pumps,flowmeter.Characterisitic:resistance to ... contact fatigue life,high hardness,resistance to wear. ceramic Si3N4 balls (bearing)