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.
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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)