Abstract: The influence of speed, energy of solid surface, slide ratio, lubricant viscosity and chemical property, etc. on film thickness in thin film lubrication are discussed. The condition under which the transition from EHL to TFL and the failure of liquid film, which is related to the pressure, viscosity and speed, take place is examined. Then, the lubrication map is proposed.

Key words: Failure of liquid film, Lubrication regime, Thin film lubrication