System of minimum lubrication with air-oil mixture fed to the cutting zone. It replaces the traditional, uneconomical cooling systems of the treatment zone based on emulsion solutions. Before the outlet nozzle, the air supplied under pressure mixes with the oil dosed in the volume of a few drops per minute. Lubricating the cutting zone with such a mixture is very effective, in addition to increasing machining efficiency and extending the tool life, it ensures cleanliness in the manufacturing environment. Start and stop of cooling are controlled automatically.