The High speed of dental drill bearing is up to 400000 R/min and it is changeable with Japanese, Germany and British products. Under normal conditions, operation life is no less than six months
   High-speed dental ball bearing is a precision miniature bearing. Careful mounting. Operation and maintainence is required to ensure its performance and service life if damages on balls or raceways occure when mounting, or bearing containating un-proper lubrication will result lower speed, large noise, strong vibration, cage fracture and shorter life. When mounting the bearing, the best fit reference of shaft and bearing bore is 0~2μm. Roundness difference ＜2μm. When press the bearing into the bore, force should be directly on the inner ring end face and not pass to raceway and steel ball. Otherwise bearing precision will be damaged. When a pair of bearing mounted on the turbine, put a few drops of labricating oil into it after washing the bearing and turbine.
　　Then install the machine head (alcohol and ace tone are not allowed for cleaning liquid.) A certain axial preload (1-2N) will be applied to the pair of bearings when installing the head. Axial run-out is not permitted after installation.
　　If axial preload too loose or too tight, change or add or reduce pad to ensure proper preload and prevent ball skid or gyro rotation in high-speed application.
　　Good maintenance of turbine head is an important factor for bearing normal operation and service life in hospital, apart from sterilization, daily cleaning and maintenance are necessary. Dismount turbine head and put it into cleaning liquid and install it again, keep the drill needle fixed, switch on the pressure air for a seconds until it passing through the bearing. Start it after lubrication.