The tribological properties of metal processing are different from those of equipment lubrication. They are often in the state of extreme pressure boundary lubrication, with high temperature and high load, and the surface of the friction pair is constantly updated in a very short time. The lubricity, cooling, rapid penetration and surface adsorption properties of the base oil will directly affect the processing efficiency and processing quality.

For metal forming, in addition to extreme pressure boundary lubrication, there is a mixed lubrication state. The viscosity of the base oil affects the formation of the oil film and needs to be considered. Moreover, the lubricity is too good and too bad is not suitable, too good will cause slipping and wrinkling, too bad to increase wear, the surface finish of the workpiece can not meet the requirements. For the cutting process, a large amount of chips are generated. The viscosity of the base oil is too large, and the adhesion is too strong, which will cause the chips and the workpiece to take away a lot of cutting fluid, and is not conducive to the cleaning of the workpiece.

Some multi-axis machine tools recently developed, the tool does not move the workpiece at high speed during machining. When selecting the cutting fluid, in addition to meeting the processing requirements, it is also necessary to consider the lubrication of the workpiece support shaft, and it is necessary to select the base oil of appropriate viscosity. Point similar equipment lubrication, otherwise it is prone to accidents.

At present, the research on the tribological properties of metal processing is not enough. The research work is concentrated on mechanical mechanics and the lubrication mechanism is less discussed. Moreover, the continuous introduction of new processes and new materials requires more attention.