An experimental study of the role of oxidation due to frictional heating in unlubricated high speed (13000 ft/min) sliding of metals is discussed. Detailed results for steel on steel have been described in another paper (1). This paper discusses a general picture correlating the results for several metal combinations and also a bonded metal carbide. The results indicate that the oxidation gives considerable protection against surface damage. With copper on copper (previously run-in), copper on steel, and bonded tungsten carbide on bonded carbide relatively little tearing of the metal (or carbide) is observed at light loads. The oxidation should increase with increasing load, and these combinations behave like steel on steel in that on at least one of the surfaces there is, if anything, even less metallic tearing at high load. At low loads wear is mild, in harmony with the oxide protection, but at higher loads severe wear is attributed to disintegration within the oxide itself. With nickel on nickel the oxidation fails to prevent fairly severe metallic tearing even at high loads. Some consequences of these phenomena in the variation of friction, wear and surface damage with load, speed and sample geometry are described.Presented as an American Society of Lubrication Engineers paper at the Lubrication Conference held in Toronto, Canada, October, 1957.