EPM vs TPU
Polymer · grade comparison
EPM and TPU are both polymer grades. TPU is the stronger of the two: tensile strength 40 MPa (5.8 ksi) against 14 MPa (2.03 ksi) for EPM, about 186% more. TPU is the more ductile: elongation 550% versus 320% for EPM. EPM is lighter (1.12 g/cm³ vs 1.18 g/cm³ for TPU) and TPU is stiffer (0.03 GPa vs 0.01 GPa).
EPMChoose it when weight is the constraint, or when the part sees heat.
TPUChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.
EPM vs TPU: 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)
Elongation at Break
Hardness, Shore A
Tear Strength
Compression Set (22 h, 70 °C)
Hardness, Shore D
Physical
Density and transition temperatures.
Density
Glass Transition (Tg)
Melting Temperature (Tm)
Water Absorption (Saturation)
Refractive Index
Same in both: Water Absorption (24 h) 0.8%
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)
Min Service Temperature
Limiting Oxygen Index
Max Service Temperature (short-term)
Vicat Softening Point (B50)
Electrical
Conductivity and insulation.
Electrical Resistivity
Dielectric Constant (1 MHz)
Dissipation Factor (1 MHz)
Volume Resistivity
Surface Resistivity
Comparative Tracking Index (CTI)
Same in both: Dielectric Strength 25 kV/mm635 V/mil
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
Formability (cold)
Mold Shrinkage
Mold Temperature (typ.)
Weldability
Polishability
Melt Flow Rate
Processing Melt Temperature (typ.)
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Same in both: Typical Recycled Content 2%
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Thermal Shock Resistance Index
Same in both: Specific Stiffness (E / density) 0 MN·m/kg · Thermal Diffusivity 0.1 mm²/s
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 | EPM | TPU |
|---|---|---|
| CNC machining | — | Yes |
| Sheet metal | — | Yes |
| Injection molding | — | Yes |
| 3D printing | — | Yes |
| Default condition | — | Shore A 85 |
| Relative cost | $$ Standard | $$ Standard |
| Min. machined wall | — | 0.5 mm |
| Best machined surface | — | Ra 0.8 µm |
| Chrome Plating (Plastic) | — | Yes |
| Conductive Coating | — | Yes |
| Dyeing (Nylon) | — | Yes |
| EMI Shielding Coating | — | Yes |
| Painting | — | Yes |
| Primer Coating | — | Yes |
| Soft Touch Coating | — | Yes |
| Spray Painting | — | Yes |
| Tinted Coating | — | Yes |
| UV Coating | — | Yes |
| Vacuum Metallization | — | Yes |
| Waterproof Coating | — | Yes |
EPM vs TPU — frequently asked
Is TPU stronger than EPM?
Yes. TPU has a typical tensile strength of 40 MPa (5.8 ksi) against 14 MPa (2.03 ksi) for EPM — about 186% more.
Which is cheaper, EPM or TPU?
Both sit in the same relative cost tier ($$, standard); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which is easier to machine, EPM or TPU?
EPM, by a small margin. Both rate poor for machinability — 30/100 against 25/100 for TPU.
Ready to make it?
Upload a CAD file and FabDigit prices the part in EPM and TPU 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.