An additive for imparting antiwear properties to a lubricant composition is based on a combination of (1) an organo borate ester composition and (2) one or more sulfur- or phosphorus-containing compounds or a non-sulfur molybdenum compound. The sulfur- or phosphorus-containing compounds are dithiocarbamate, bisdithiocarbamate, 1,3,4-diathiazole, phosphorodithioate, phosphorodithioate esters, and the molybdenum compound is prepared by reacting (a) about 1.0 mole of fatty oil having 12 or more carbon atoms, (b) about 1.0 to 2.5 moles diethanolamine and (c) a molybdenum source.