Measurements of friction and wear during sliding of specimens of Nimonic 75, C263, Nimonic 108 and Incoloy 901 on like specimens in air at temperatures from 20 to 800 C are presented. Under the sliding conditions used, all the alloys show a transition temperature, above which low wear and a low coefficient of friction during sliding are observed after a time and below which these parameters remain relatively high throughout. These temperatures are about 150 C for N75, about 200 C for C263 and N108 and between 200 and 300 for Incoloy 901. At given temperatures above the transition temperatures, the coefficient of friction-time loci show sharp, generally very reproducible, changes from relatively high to low coefficients of friction. The times at which these occur decrease with increasing temperature for a given alloy. Such changes can be closely correlated to the formation of a stable, adherent, thermally softened, oxide layer or glaze on the load-bearing areas during sliding. Once the glaze is established, very little further wear takes place. These tribological properties of the glaze are associated with its low shear strength and the high strength of the underlying alloy substrate. They depend more on its physical properties than on its precise chemical composition. It is concluded that high strength, relatively rapid transient oxidation rates, and appropriate physical properties of the resulting oxide films are important qualities in alloys employed under sliding conditions in air at elevated temperatures.Presented as an American Society of Lubrication Engineers paper at the ASLE/ASME Lubrication Conference held in Atlanta, Georgia, October 16–18, 1973