The life of bearings is mainly affected by the efficiency of its lubrioation,for bearings operating under severe conditions such as high vacuum and temperature,conventional lubrication presents many problems. Perwenent thin soft metal-films give a solution to this problem. A rig was built to measure the friction torque for ball thrust bearings operating in vacuum. This paper describes an investigation of the friction toraue of thrust bearings covered by thin lead and silver films operating in vacuum. The effeat of normal load and ball-track conformity. have been studied,It is shown that the friction torque for the uncoated bearings increases when operating in vacuum especially for high values of ball-track conformity,lt is also shown that the coating decreaaes the friction torque for all values of ball-track conformity and the value of the friction toroue for these bearings does not increase when operating in vaouum.