What You Need to Know About POM
2026/5/15
Key Takeaways
POM's excellent self-lubricating properties and wear resistance make it a strong choice for sliding components.
POM machines cleanly with minimal burring—and any burrs that do form are easy to remove.
Standard-grade POM has poor weather resistance and is not recommended for outdoor use.
POM Material Properties
Property | Unit | Test Method | Homopolymer | Copolymer |
|---|---|---|---|---|
Specific Gravity | — | D792 | 1.42 | 1.41 |
Tensile Strength | MPa | D638 | 75 | 62 |
Elongation at Break | % | D638 | 30 | 50 |
Impact Strength (Izod, Notched) | J/m | D256 | 80 | 100 |
Hardness (Rockwell) | — | D785 | R120 | R115 |
Coefficient of Linear Thermal Expansion | ×10⁻⁵/°C | D696 | 9 | 10 |
Continuous Service Temperature | °C | — | 90 | 90 |
Volume Resistivity | Ω·cm | D257 | 6×10¹² | 6×10¹² |
Dielectric Strength | KV/mm | D149 | 13–15 | 20 |
Overview of POM
POM (polyoxymethylene) is an engineering plastic recognized for its excellent mechanical strength, wear resistance, and chemical resistance. It machines cleanly with minimal burring—and any burrs that form are easy to remove—making it a great fit for precision components.
POM is also highly resistant to moisture absorption, which means it experiences very little dimensional change due to water or humidity uptake. It's an extremely versatile material and, alongside MC Nylon, is one of the most frequently considered options when selecting a plastic for machined parts.
Excellent mechanical strength and wear resistance
Good heat resistance
Electrical insulation
Excellent chemical resistance
Strong cost-to-performance ratio
Grades of POM
Beyond the standard grade, POM is available in a range of specialty grades with enhanced properties:
Standard Grade
UV-Resistant Grade
Low-Friction / Sliding Grade
Glass Fiber Reinforced Grade
Medical Grade
Carbon Fiber Reinforced (Conductive) Grade
High-Load Sliding Grade
Material Selection Considerations
Standard-grade POM has poor weather resistance and is not suitable for outdoor applications. While it is slow-burning, its oxygen index of 15 means it is still flammable, so it should not be used in environments with open flames or significant heat sources.
Although POM generally has low water absorption, some grades can actually absorb more moisture than expected. For example, the high-load sliding grade POM SW-01 has a water absorption rate of 0.6%, while the MC Nylon sliding grade MC703HL sits at 0.5% — meaning the POM grade absorbs slightly more in this case.
Since physical properties can vary between grades, always consult the latest material data sheet from the manufacturer when finalizing your material selection. This will help ensure the best possible match for your specific application.
Low weather resistance
Flammable
Step Up Your Project with Yumoto Electric
Yumoto Electric manufactures custom POM machined parts starting from a single piece. We have experience with over 200 materials, including metals such as aluminum alloys, stainless steel, molybdenum, and titanium; and engineering plastics including PEEK, PPS, and MC Nylon.
If you’re unsure about material selection or machining methods, we offer complimentary consultations to help optimize your design and production. For any questions, please feel free to contact us.
