POM vs RTPU
Polymer · grade comparison
POM and RTPU are both polymer grades. POM is the stronger of the two: yield strength 62 MPa (8.99 ksi) against 52 MPa (7.54 ksi) for RTPU, about 19% more; tensile strength follows at 63 MPa (9.14 ksi) vs 58 MPa (8.41 ksi). In exchange, RTPU is the more ductile: elongation 140% versus 30% for POM. RTPU is lighter (1.2 g/cm³ vs 1.41 g/cm³ for POM) and POM is stiffer (2.8 GPa vs 2.1 GPa). On the shop floor, POM machines more easily (excellent vs good), RTPU welds better (very good vs good), and POM sits in a lower cost tier (standard, $$) than RTPU (premium, $$$).
POMChoose it when strength drives the design, or when the part sees heat.
RTPUChoose it when the part is bent, formed or impact-loaded, or when weight is the constraint.
POM vs RTPU: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all polymer grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all polymer grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Elastic (Young's) Modulus
Shear Modulus
Bulk Modulus
Poisson's Ratio
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Compressive Strength
Compressive Modulus
Flexural Strength
Flexural Modulus
Shear Strength
Fracture Toughness (K_IC)
Izod Impact, Notched
Hardness, Shore D
Hardness, Rockwell M
Hardness, Rockwell R
Physical
Density and transition temperatures.
Density
Melting Temperature (Tm)
Glass Transition (Tg)
Water Absorption (24 h)
Water Absorption (Saturation)
Refractive Index
Light Transmission
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Specific Heat Capacity
Thermal Expansion (CTE, 20–100 °C)
Max Service Temperature (continuous)
Heat Deflection Temp. @ 0.45 MPa
Heat Deflection Temp. @ 1.8 MPa
Vicat Softening Point (B50)
Limiting Oxygen Index
Max Service Temperature (short-term)
Same in both: Min Service Temperature -40°C-40 °F
Electrical
Conductivity and insulation.
Dielectric Strength
Dielectric Constant (1 MHz)
Dissipation Factor (1 MHz)
Same in both: Electrical Resistivity 1×10¹² Ω·m3.94×10¹⁹ µΩ·in · Volume Resistivity 1×10¹⁴ Ω·cm · Surface Resistivity 1×10¹⁴ Ω · Comparative Tracking Index (CTI) 600 V
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
UV / Weathering Resistance
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Weldability
Formability (cold)
Polishability
Mold Shrinkage
Melt Flow Rate
Processing Melt Temperature (typ.)
Mold Temperature (typ.)
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Same in both: Typical Recycled Content 0%
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Modulus of Resilience
Same in both: Thermal Diffusivity 0.1 mm²/s · Thermal Shock Resistance Index 0
Strength versus weight
Yield strength against density for every polymer grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
Manufacturing and finishing
| Capability | POM | RTPU |
|---|---|---|
| Injection molding | Yes | — |
| Default condition | Unfilled | — |
| Relative cost | $$ Standard | $$$ Premium |
| Min. machined wall | — | — |
| Best machined surface | — | — |
| Chrome Plating (Plastic) | Yes | — |
| EMI Shielding Coating | Yes | — |
| Soft Touch Coating | Yes | — |
| Spray Painting | Yes | — |
| UV Coating | Yes | — |
POM vs RTPU — frequently asked
Is POM stronger than RTPU?
Yes. POM has a typical yield strength of 62 MPa (8.99 ksi) against 52 MPa (7.54 ksi) for RTPU — about 19% more. Tensile strength is 63 MPa (9.14 ksi) vs 58 MPa (8.41 ksi).
Which is cheaper, POM or RTPU?
POM is the lower-cost material: it sits in the standard tier ($$) while RTPU is premium ($$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.
Which is easier to machine, POM or RTPU?
POM. Its machinability rates excellent (88/100) against good (55/100) for RTPU; for welding the order is RTPU first (very good, 70/100) then POM (good, 55/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in POM and RTPU side by side — material, machining time, tolerance and finish in one quote. Certified material data ships with the order on request.
Typical handbook values for the conditions named above, normalised for comparison. Hardness on non-Brinell scales is converted approximately for charting only. Request certified data with your order for design-critical properties.