A lubricating grease composition comprises a mixture of two component greases, component (1) comprising a lubricating oil thickened to a grease consistency with a complex of a metal salt and a metal soap or of two or more metal salts and component (2) comprising a lubricating oil thickened to a grease consistency with a lithium soap optionally in admixture with other metal. The complex of component (1) may be (a) a soap-salt complex prepared from a metal soap of a C12-C30 carboxylic acid and a metal salt of a C1-C3 carboxylic acid; (b) a soap-salt complex prepared from a metal soap of a C12-C30 carboxylic acid, a metal salt of a C3-C10 carboxylic acid and a metal salt of acetic acid; or (c) a mixed salt complex prepared from a metal salt of a C7-C10 carboxylic acid and a metal salt of a C1-C3 carboxylic acid. Specified C1-C3 acids are formic, acetic, propionic and lactic acids, while C3-C10 acids mentioned are alkane monocarboxylic acids and glyceric, lactic, citric, benzoic, hydroxybenzoic, toluic, phthalic, terephthalic, furoic and thiophene carboxylic acids. The C7-C10 acids mentioned are alkane monocarboxylic acids, while the C12-C30 acids are saturated or unsaturated fatty acids. The metal component of the complexes may be calcium, barium, strontium, magnesium or zinc. The lithium soap of component (2) may be a fatty acid soap. Mixtures of lithium and strontium or lithium and calcium soaps may be employed in component (2). The lubricating oils of components (1) and (2) may be mineral or synthetic. Examples of synthetic oils are hydrocarbons, hydrocarbon polymers, esters (e.g. di-2-ethylhexyl sebacate or di-C8 oxo acelate), complex esters, formals, mercaptals, polyalkylene oxides and silicones. In examples: (A) a grease (1) prepared from mineral lubricating oil, acetic acid, hydrogenated castor oil, hydrogenated fish oil fatty acids, hydrated lime and phenyl alpha naphthylamine is blended with a grease (2) prepared from mineral lubricating oil, tallow fatty acids, hydrated lime and lithium hydroxide monohydrate; and (B) a grease (1) prepared from mineral lubricating oil, acetic acid, caprylic acid, hydrated lime and phenyl alphanaphthylamine is blended with a grease (2) prepared from mineral lubricating oil, methyl 12-hydroxy stearate, lithium hydroxide monohydrate and phenyl alpha naphthylamine.
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