Properties of Polyoxymethylene (POM)
Polyoxymethylene (POM), also known as acetal, polyacetal, and polyformaldehyde, is a high-performance engineering thermoplastic. It is a type of polymer with a repeating unit composed of formaldehyde, and it belongs to the family of polyoxymethylenes. POM is known for its high stiffness, excellent dimensional stability, low friction, and good wear resistance.
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 icon 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)
Related Pages
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.