Cylindrical roller bearings containing silicon nitride ceramic rolling elements have been commercially available since the early 1990’s. Silicon nitride is key to the cylindrical bearing because of its high compressive strength, contact fatigue resistance that is superior to bearing steels, electrical resistivity and low coefficient of friction versus bearing steel. These properties allow cylindrical bearings to operate with reduced or no lubrication, at higher stress levels or higher speeds, and under conditions that are not favorable to steel bearings.



Cylindrical roller bearings can be smaller than steel bearings for the same application and they operate with reduced audible noise levels. Ceradyne customers use these roller bearings in machine tool spindles and in the Formula 1 gearbox.