Dental handpiece bearing Dental Bearing Dental handpiece bearing Product 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 under the normal operation. *Weak acid resistant, Weak base resistant.. *Corrosion resistant, High-temperature resistant.. *Perfectly usable for many brands of handpiece, such as KAVO,NSK,W&H,BIEN AIR, MIDWEST,STAR,FARO,ADEC,SIEMENS,LARES,etc.. .