POM and PA materials have good mechanical strength and wear resistance, and are suitable for making relatively precise plastic bearings. The working temperature is from -60℃~l00℃, the surface strength is high and smooth, and there is basically no tension. Its good self-lubricating performance and low friction coefficient can be used for precision and high speed operation on the basis of maintaining the traditional advantages of plastic bearings. Among them, POM plastic bearings are the most widely used one of all plastic bearings. Generally, the inner and outer ring materials are POM or PA, and the cage is made of glass fiber reinforced nylon 66 (GRPA66-25), and the balls are glass balls, stainless steel balls or ceramic balls. This bearing is suitable for contact with food and performs well in alkaline environments but is not suitable for operating in acidic corrosion and strong oxidant environments.