Polyoxymethylene (POM) is an engineering plastic with excellent performance. It is known as "seizing steel" and "super steel". It has the hardness, strength and rigidity similar to metals. It has good self-lubricating property, good fatigue resistance, elasticity and good chemical resistance in a wide range of temperature and humidity. It is widely used in electronic and electrical, machinery, instruments Daily light industry, automobile, building materials, agriculture and other fields.