A lubricating composition, especially suitable for use in the crank cases or gear cases of automobiles and in the metal working industry, comprises a major proportion of a mineral lubricating oil, a minor proportion of a stable oil-soluble extreme pressure addition agent and a minor proportion of an oil-soluble corrosion inhibitor comprising a sulphur-bearing amine containing only the elements carbon, hydrogen, sulphur and nitrogen. The E.P. addition agent has a vapour pressure less than atmospheric at 140 DEG C., substantially increases the load-carrying ability of the lubricating composition and is dependent for its effectiveness on its ability to react chemically with the metallic surfaces to be lubricated. The corrosion inhibitor is one characterized by the fact that its inclusion in the lubricating composition does not substantially decrease the extreme pressure properties imparted to the composition by the E.P. addition agent. The corrosion inhibitors mentioned are thioamines, including aryl thioamines such as the thiophenylamines, and particularly thiodiphenylamine. E.P. addition agents mentioned are (a) halogenated aliphatic compounds such as C Cl4, C2 Cl4, C2 Cl6 C2HCl3, C2HCl5, (C2H4Cl)2O, C17H33Cl2COOH, and halogenated petroleum fractions, particullarly chlorinated paraffin wax (b) halogenated cyclic organic compounds such as naphthalene tetrachloride, dichlorodihydrobenzene (C6H6Cl2), tetrachlorotetrahydrobenzene (C6H6Cl4), hexa-chloro-cyclohexane, monochloro addition product of diphenyl ether (C12H10ClO), dichloro addition substitution product of diphenyl ether (C12H9Cl2O), nonochloro addition substitution product of diphenyl ether (C12H7Cl9O), pentachloro addition substitution product of diphenyl ether (C12H6Cl5O), chloro-benzoic acid, chloronitrobenzene, benzyl chloride and phenyl ethyl chloride, (c) organic poly-sulphides, (d) substances of the formula RNH2. H2S where R is an organic group, (e) sulphur chloride-treated oils (whether mineral or non-mineral) and fatty acids, (f) free sulphur, (g) fatty acids such as oleic and stearic acids, naphthenic acids and halogen-bearing substitution products of such acids. The lubricating composition may also contain soaps, pour-point depressors, anti-oxidants, oiliness agents, non-mineral oils and fatty acids such as oleic acid. In an example, a mineral lubricating oil composition is described containing benzyl chloride and thiodiphenylamine. The Specification as open to inspection under Sect. 91 refers to the use of benzyl thiocyanate, thiourea, thiocarbanilide and other nitrogen and sulphur-containing compounds as the corrosion inhibitor. This subject-matter does not appear in the Specification as accepted.