Dalian precision machining is divided into cold machining and hot machining according to the temperature state of the workpiece being processed. 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.

Hot working commonly includes heat treatment, forging, casting and welding. The former pursues the machining accuracy and surface quality limit, and the latter includes the automation of product design, manufacturing and management. It is not only an important means to quickly respond to market demand, improve productivity and improve labor conditions, but also an effective measure to ensure product quality. The two are closely related.

Many precision and ultra precision machining rely on automation technology to achieve the expected indicators, and many manufacturing automation rely on precision machining to achieve accurate and reliable. They play an overall and decisive role and are the pillars of technology. It is realized by using precision machine tools and precision measuring tools and meters. Ultra precision machining is called ultra precision machining when the machining accuracy reaches or exceeds 0.1 micron.

The micro unevenness of part surface (average height difference of surface unevenness) is less than 0.1 micron. Some parts can also meet the requirements of accurate mechanical or other physical characteristics, such as the torsional stiffness of the torsion bar of the float gyroscope, the stiffness coefficient of the flexible element, etc. High mutual position accuracy is obtained by relying on the accuracy of guide rail and spindle of machine tool. Accurate mirror surface can be obtained by high-speed milling with carefully ground diamond cutter head. It is also related to the selection and balance of grinding wheel and the machining accuracy of workpiece center hole. The dimensional accuracy of 1 micron and out of roundness of 0.5 micron can be obtained by fine grinding.