Polyoxymethylene (POM), also known as acetal, polyacetal, and polyformaldehyde, is an engineering thermoplastic used in precision parts that require high stiffness, low friction, and excellent dimensional stability. POM is characterized by its high strength, hardness and rigidity to -40 °C / -40 °F. POM is intrinsically opaque white, due to its high crystalline composition, but is available in all colors.
The POM homopolymer is a semi-crystalline polymer with a melting point of 175 °C / 347 °F, whereas the copolymer has a slightly lower melting point of 162 °C to 173 °C / 323 °F to 343 °F.
POM is a tough material with a very low coefficient of friction. It is sensitive to oxidation, and an anti-oxidant is normally added to molding grades of the material. The two most common forming methods employed are injection molding and extrusion. Typical applications for injection-molded POM include high-performance engineering components, and the material is widely used in the automotive and consumer electronics industries. POM is suitable for heavy conveying applications and low temperatures.