GREASE COMPOSITION

A composition which comprises (a) a salt of monovalent metal (M) of a carboxylic acid in which the COOH group is attached to a ring atom of a fused ring system and (b) a grease which is a non-soap thickened oil which may be a mineral oil or a synthetic oil such as a silicone oil. The metal (M) may be sodium. The fused ring system is preferably a fused aromatic hydrocarbon ring system such as naphthalene and may include further substituents, for example an -OH group, in addition to the COOH group. If the acid contains both OH and COOH groups, these can be attached to adjacent atoms of the fused ring system. podium 2-naphthoate and sodium 3-hydroxy-2-alaphthoate have been found to be particularly suitable. The grease has improved corrosion resistance and the addition of the metal compound does not result in destructing of tie grease.