Lubricating oil composition serving as sliding surface oil and metal working oil, and method of lubricating working machinery using said oil composition

A method of lubricating a metal working machine which has (i) at least one sliding machine surface requiring lubrication and (ii) a metal working section wherein metal is worked in contact with a metal working fluid, and, wherein the operation of said machine causes the sliding machine surface lubrication to mix with the metal working liquid, said method comprising applying a lubricating oil composition to said at least one sliding surface and using as said metal working fluid an aqueous working fluid composition comprising said lubricating oil composition diluted with water, the ratio of water to said lubricating oil composition being at least 3 to 1, said lubricating oil composition comprising:

• (A) 5 to 88% by weight of at least one oil selected from the group consisting of a mineral oil and synthetic oil,
• (B) 2 to 50% by weight of a reaction product of a long chain dibasic acid of the formula ##STR4## and a C.sub.2 -C.sub.4 alkanolamine present in a molar ratio of 1:0.5 to 5,
• (C) 5 to 30% by weight of at least one extreme pressure additive selected from the group consisting of sulfurized fat and oil, a phosphate, a phosphite, and an amine salt of phosphate or phosphite, and
• (D) 5 to 30% by weight of an emulsifying agent selected from the group consisting of an anionic surface active agent, a cationic surface active agent, a nonionic surface active agent and a phosphorus-containing surface active agent.