Polymethacrylate POM, also known as polyformaldehyde, is commonly referred to as "Sai Gang" or "Te Ling." It is a high-crystalline polymer composed of homopolymers with molecular chains formed by formaldehyde, and copolymers formed by trioxacyclopentane, ethylene oxide, and others. POM features a smooth and glossy surface, low water absorption, dimensional stability, good wear resistance, high strength, excellent self-lubricating properties, and good coloring ability. It is also resistant to oil and peroxides. Different production processes can create various types of homopolymers and copolymers of POM. The mechanical properties of POM are slightly temperature-sensitive, with copolymer POM showing slightly more variation than homopolymer POM. POM has high impact strength but is not as good as ABS and PC in standard impact tests; it is also sensitive to notches, which can reduce impact strength by up to 90%. It is widely used in the manufacture of various sliding and rotating mechanical parts, including gears, levers, pulleys, sprockets, and is particularly suitable for bearings. It is also used in hot water valves, precise metering valves, conveyor chain rings and rollers, flowmeters, automotive interior and exterior handles, cranks, and other window operating mechanisms. Additionally, it is used in oil pump bearing seats and impellers, gas switches, electronic switch components, terminal mirror covers, fan parts, heating plates, meter buttons, and more.