Improvements in or relating to lubricants

A lubricant for preventing corrosion of working parts of rock drills &c. by corrosive liquids or vapours comprises a lubricating oil containing (a) a blown fatty oil or wool wax, and (b) one or more of the soaps of aluminium, barium, calcium, chromium, cobalt, copper, iron, lead, nickel, potassium, sodium, thallium or zinc added in such proportions that the lubricant is capable of absorbing the corrosive liquid or vapour to form an emulsion in which the oil is in the continuous phase. The metal soaps are preferably added in an amount exceeding 0,25 per cent of the weight of the oil. Suitable fatty acids for forming the metal soaps comprise oleic, palmitic, stearic, mixed fatty acids from vegetable fish or animal oils, carboxylic acids of cyclic compounds, naphthenic acids. Soaps of the alkali metals are included in such small amounts that the emulsions are of the water-in-oil type. Examples of suitable lubricants are (1) 90 per cent mineral oil, 10 per cent wool wax, 0,25 per cent lead oleate, 0,10 per cent chromium oleate, (2) 85 per cent mineral oil, 15 per cent wool wax, 0,25 per cent lead oleate, 0,10 per cent chromium oleate.