Properties of Polyoxymethylene (POM)
Polyoxymethylene (POM), also known as acetal or polyacetal, is a high-performance engineering thermoplastic valued for its strength, stiffness, and low friction. This semi-crystalline polymer offers excellent dimensional stability and wear resistance, making it ideal for precision parts in mechanical and automotive applications.
The following table provides a comprehensive list of polyoxymethylene (POM) properties in both SI and US customary/Imperial units at normal temperature and pressure (NTP).
Click on the button to switch between Metric and Imperial units.
Physical Properties | Metric |
---|---|
Category | Thermoplastic |
Density | 1400 kg/m3 |
Water Absorption | 0.2 %wt/day |
Mechanical Properties | Metric |
Ultimate Tensile Strength | 69 - 83 MPa |
Yield Tensile Strength | 65 - 69 MPa |
Ultimate Compressive Strength | 110 MPa |
Young’s Modulus (E) | 2.9 - 3.2 GPa |
Flexural Modulus | 2.41 - 3.10 GPa |
Elongation at Break | 40 - 75% |
Rockwell Hardness (R) | 120 |
Thermal Properties | Metric |
Melting Point | 175 °C |
Thermal Conductivity | 0.37 W/m·K |
Specific Heat Capacity (Cp) | 1464 J/kg·K |
Coefficient of Thermal Expansion (αL) | 8.5×10-5 1/°C |
Electrical Properties | Metric |
Relative Permittivity (@1 MHz) (εr) | 3.8 |
Electrical Resistivity | 1015 Ω·cm |
Dielectric Field Strength (Ed) | 200 kV/cm |
Hazardous Data | Metric |
Flammability Rating (ANSI/UL 94) | HB |
Unless stated otherwise, all values are taken at room temperature (approximately 20°C or 68°F) and 1 atm pressure. (1 atm = 101,325 Pa)
References: 1) Cardarelli, François. Materials Handbook: A Concise Desktop Reference. Switzerland: Springer International Publishing, 2018. 2) CRC Handbook of Chemistry and Physics, 97th Edition. United Kingdom: CRC Press, 2016-2017. 3) A.M. Howatson, P.G. Lun, J.D. Todd, P.D. Engineering Tables and Data. United Kingdom: University of Oxford, Department of Engineering Science, 2009.