Machining is a process of changing the overall dimension or performance of a workpiece with a machining machine. According to the temperature state of the workpiece to be processed, it is divided into cold processing and hot processing. Generally, it is processed at normal temperature without causing chemical or phase changes of the workpiece, which is called cold processing. Generally, processing above or below normal temperature will cause chemical or phase changes of the workpiece, which is called hot processing.

Cold working can be divided into cutting and pressure machining according to the difference of machining methods. Heat treatment, forging, casting and welding are common in hot working. Compared with ordinary lathe, CNC lathe has the function of constant linear speed cutting. No matter for the end face or the outer circle with different diameters, it can be processed with the same linear speed, that is, the surface roughness value is consistent and relatively small.

The ordinary lathe has a constant speed, and the cutting speed is different with different diameters. When the material, finishing allowance and tool angle of workpiece and tool are certain, the surface roughness depends on the cutting speed and feed speed. In the aerospace industry, Dalian precision machining is mainly used to process precision mechanical parts in aircraft control equipment, such as precision mating parts in hydraulic and pneumatic servo mechanisms, gyroscope frames, shells, air and liquid floating bearing components and floats. The structure of aircraft precision parts is complex, the stiffness is small, the precision is very high, and the proportion of difficult to process materials is large.

The machining process benchmark of precision machinery parts can be divided into: casting, forging, stamping, welding, heat treatment, machining, assembly and so on. It refers to the general name of the whole part NC machining and machine assembly process. Others, such as cleaning, inspection, equipment maintenance, oil seal and so on, are only auxiliary processes. Turning methods change the surface properties of raw materials or semi-finished products. NC machining process is the main process in the industry.

Production process refers to the whole process of making products from raw materials (or semi-finished products). For machine production, it includes the transportation and preservation of raw materials, production preparation, blank manufacturing, parts processing and heat treatment, product assembly, commissioning, painting and packaging, etc. The content of production process is very extensive. Modern enterprises use the principles and methods of system engineering to organize and guide production, and regard the production process as a production system with input and output.