Precision and special machining is a multidisciplinary and advanced technology. To obtain high-precision and high-quality machined surfaces, not only the machining method itself must be considered, but also the workpiece material, machining equipment and process equipment, testing methods, working environment, and human technical level involved. The combination of precision and special processing technology with system theory, methodology, computer technology, information technology, sensor technology, and digital control technology has facilitated the formation of precision and special processing system engineering.

Precision machining includes microfabrication, finishing, and precision machining, and is closely related to special machining.

Special machining refers to non-traditional machining methods (NTM) that utilize energy sources such as machinery, light, electricity, sound, heat, chemistry, magnetism, and atomic energy for machining. Their main differences from traditional cutting include:

① Mainly not relying on mechanical energy, but mainly using other energies (such as electrical energy, thermal energy, light energy, sound energy, and chemical energy) to remove workpiece materials;

② The hardness of the cutting tool can be lower than that of the workpiece material being processed. In some cases, such as laser processing, electron beam processing, ion beam processing, etc., no tools are needed at all;

③ During the machining process, there is no significant mechanical cutting force between the tool and the workpiece, and the workpiece does not bear mechanical force, making it particularly suitable for precision machining of low stiffness parts.

Due to the above characteristics, overall, special processing technology can process any metal, non residual material or composite material with hardness, strength, toughness, brittleness, and is particularly suitable for processing complex, micro surface and low stiffness parts. At the same time, some methods can also be used for ultra precision processing, mirror processing, finishing processing, and nanoscale (atomic level) processing.