color black material SSiC 1.we are the pioneer of ceramic bearing in China 2.material is SSiC 3.full ceramic bearing 4.we ... ,low temp,electric insulation,high precision ballscrew set,valve balls for acid,alkali,salt,measure pumps,flowmeter.Characterisitic:resistance to strong ... to hydrofluoric acid,long life,high hardness,resistance to wear. ceramic shaft for pump