the objective of the task was to evaluate the suitability of a bronze-filled polytetra fluoroethylene (salox m) as the cage material in space shuttle main engine (ssme) high pressure oxygen turbo pump (hpotp) bearings. the role of the cage pocket material will be to provide a transferred lubricating interface at the ball-race contact region. a series of experiments was conducted which involved block-on-ring tests (the block was the polytetrafluoroethylene (ptfe) -filled material and the ring was through-hardened 440c steel) and high speed traction tests of two 440c disks with one disk rubbed with a ptfe block to generate a transfer film. measurements included post test visual observations of the condition of the 440c, wear rate measurements of the blocks, and traction measurements between the disks. it was observed that both salox m and glass-filled ptfe (armalon) transferred ptfe to 440c at cryogenic temperatures. bronze is also transferred to uncoated 440c from the salox m. at room temperature no ptfe transfer was observed in the high speed disk tests due to severe frictional heating, although bronze transfer still occurred with the bronze-ptfe salox m material. since the bearing will operate at cryogenic temperature, transfer films are very probable. salox m wore slightly, although probably tolerably, more than glass-filled ptfe against 440c. however, salox m is clearly less abrasive to 440c than is the glass-filled material. when the surface layer of ptfe is depleted from the glass-filled material, the glass fibers tend to seriously abrade the steel. this problem does n