Dental bearing is miniature ball bearing,to be perfectly usable for high-speed dental turbine handpiece Dental bearing/dental bearing/Dental handpiece bearingProduct Specifications*Rings AISI 440C stainless steel: 9Cr18 for inner ring and outer ring Balls: Si3N4 Ceramic balls or stainless steel balls*Rotating speed 350,000-450,000 rpm under air-pressure of 200-250Kpa*Working life about six months ...