The five-ball fatigue tester was used to determine the rolling-contact fatigue life of 1/2-inch-diameter M-1 steel balls with four lubricants at 300 deg F. Film thickness measurements were made with the rolling-contact disk machine under simulated five-ball test conditions. Under certain conditions, elastohydrodynamic lubrication was found to exist at initial maximum Hertz stress levels up to 800,000 psi. There appears to be a correlation among the following variables: Plastically deformed profile radius of the ball specimen at ambient temperature; lubricant type; and rolling-contact fatigue. No correlation was found between contact temperature obtained with different lubricants and fatigue life.