(EP additive). (1) Material added to cutting fluids to impart high film strength. They are mainly sulfur, chlorine, and occasionally phosphorus compounds. Actual conditions, amounts, etc. are proprietary. (2) Lubricating oil and grease additives that prevent metal-to-metal contact in highly loaded gears. Some react with the metal gears to form a protective coating. Saponified lead salts are often used.