PU Cast vs TPU
Polymer · grade comparison
PU Cast and TPU are both polymer grades. TPU is the stronger of the two: tensile strength 40 MPa (5.8 ksi) against 12 MPa (1.74 ksi) for PU Cast, about 3.3 times as much. In exchange, PU Cast is the more ductile: elongation 700% versus 550% for TPU, and TPU is harder (33 Shore D vs 10 Shore D). PU Cast is lighter (1.1 g/cm³ vs 1.18 g/cm³ for TPU) and TPU is stiffer (0.03 GPa vs 0 GPa). On the shop floor, TPU welds better (excellent vs poor).
PU CastChoose it when the part is bent, formed or impact-loaded, or when weight is the constraint.
TPUChoose it when strength drives the design, or when it will be welded.
PU Cast 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
Compressive Strength
Shear Strength
Hardness, Shore A
Hardness, Shore D
Tear Strength
Compression Set (22 h, 70 °C)
Physical
Density and transition temperatures.
Density
Glass Transition (Tg)
Water Absorption (24 h)
Water Absorption (Saturation)
Refractive Index
Melting Temperature (Tm)
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Specific Heat Capacity
Thermal Expansion (CTE, 20–100 °C)
Limiting Oxygen Index
Vicat Softening Point (B50)
Same in both: Max Service Temperature (continuous) 80°C176 °F · Min Service Temperature -40°C-40 °F · Max Service Temperature (short-term) 120°C248 °F
Electrical
Conductivity and insulation.
Electrical Resistivity
Dielectric Strength
Volume Resistivity
Surface Resistivity
Comparative Tracking Index (CTI)
Same in both: Dielectric Constant (1 MHz) 5 · Dissipation Factor (1 MHz) 0.05
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
UV / Weathering Resistance
Same in both: Corrosion Resistance 78 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Weldability
Formability (cold)
Polishability
Mold Shrinkage
Processing Melt Temperature (typ.)
Mold Temperature (typ.)
Melt Flow Rate
Same in both: Machinability 25 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Typical Recycled Content
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 | PU Cast | TPU |
|---|---|---|
| CNC machining | — | Yes |
| Sheet metal | — | Yes |
| 3D printing | — | Yes |
| Default condition | Shore A 40 | Shore A 85 |
| Relative cost | $$ Standard | $$ Standard |
| Min. machined wall | — | 0.5 mm |
| Best machined surface | — | Ra 0.8 µm |
| Conductive Coating | — | Yes |
| Dyeing (Nylon) | — | Yes |
| Painting | — | Yes |
| Primer Coating | — | Yes |
| Tinted Coating | — | Yes |
| Vacuum Metallization | — | Yes |
| Waterproof Coating | — | Yes |
Both are offered for Injection molding. They share 5 finishes: Chrome Plating (Plastic), EMI Shielding Coating, Soft Touch Coating, Spray Painting, UV Coating.
PU Cast vs TPU — frequently asked
Is TPU stronger than PU Cast?
Yes. TPU has a typical tensile strength of 40 MPa (5.8 ksi) against 12 MPa (1.74 ksi) for PU Cast — about 3.3 times as much.
Which is cheaper, PU Cast 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 welds better, PU Cast or TPU?
TPU. Its weldability rates excellent (85/100) against poor (15/100) for PU Cast.
Ready to make it?
Upload a CAD file and FabDigit prices the part in PU Cast 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.