The behavior of several solid film lubricants has been experimentally established as a function of temperature. These films are formed of a suspension of lubricant particles (graphite, molybdenum disulfide) in a thermosetting resin baked onto a hard surface. The test consists of heating such a layer and continually observing the friction coefficient until failure. Sliding conditions of high unit loading and low rubbing velocity were chosen to provide a comparison between the films. They were evaluated as to the highest temperature for which the friction coefficient remained low and subsequently as to the number of load cycles sustained at temperature before an abrupt increase in friction. Results for all films were similar in that failure was caused by a breakdown of the binder rather than the lubricating particles and that the minimum friction coefficient (∼ 0.03) was observed just before the film failure at temperatures as high as 1200° F.Presented as an American Society of Lubrication Engineers paper at the Lubrication Conference held in Toronto, Canada, October, 1957.