PU Cast vs PU Foam
Polymer · grade comparison
PU Cast and PU Foam are both polymer grades. PU Cast is the stronger of the two: tensile strength 12 MPa (1.74 ksi) against 0.13 MPa (0.0189 ksi) for PU Foam, about 92 times as much. PU Cast is the more ductile: elongation 700% versus 150% for PU Foam. PU Foam is lighter (0.03 g/cm³ vs 1.1 g/cm³ for PU Cast) and PU Cast is stiffer (0 GPa vs 2×10⁻⁴ GPa). On the shop floor, PU Foam machines more easily (excellent vs poor), PU Foam welds better (30 vs 15 out of 100), and PU Foam sits in a lower cost tier (budget, $) than PU Cast (standard, $$).
PU CastChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.
PU FoamChoose it when weight is the constraint, or when the part sees heat.
PU Cast vs PU Foam: 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
Water Absorption (24 h)
Water Absorption (Saturation)
Refractive Index
Same in both: Glass Transition (Tg) -50°C-58 °F
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)
Limiting Oxygen Index
Same in both: Min Service Temperature -40°C-40 °F · Max Service Temperature (short-term) 120°C248 °F
Electrical
Conductivity and insulation.
Electrical Resistivity
Dielectric Strength
Dielectric Constant (1 MHz)
Dissipation Factor (1 MHz)
Volume Resistivity
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
Processing Melt Temperature (typ.)
Mold Temperature (typ.)
Same in both: Mold Shrinkage 1.5%
Sustainability
Primary-production footprint per kilogram.
Embodied Carbon (primary production)
Embodied Water
Typical Recycled Content
Same in both: Embodied Energy (primary production) 102 MJ/kg43,852 BTU/lb
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Thermal Diffusivity
Thermal Shock Resistance Index
Same in both: Specific Stiffness (E / density) 0 MN·m/kg
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 | PU Foam |
|---|---|---|
| Default condition | Shore A 40 | Open Cell |
| Relative cost | $$ Standard | $ Budget |
| Min. machined wall | — | — |
| Best machined surface | — | — |
Both are offered for Injection molding. Both take the same 5 finishes: Chrome Plating (Plastic), EMI Shielding Coating, Soft Touch Coating, Spray Painting, UV Coating.
PU Cast vs PU Foam — frequently asked
Is PU Cast stronger than PU Foam?
Yes. PU Cast has a typical tensile strength of 12 MPa (1.74 ksi) against 0.13 MPa (0.0189 ksi) for PU Foam — about 92 times as much.
Which is cheaper, PU Cast or PU Foam?
PU Foam is the lower-cost material: it sits in the budget tier ($) while PU Cast is standard ($$). 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, PU Cast or PU Foam?
PU Foam. Its machinability rates excellent (90/100) against poor (25/100) for PU Cast; for welding the order is PU Foam first (poor, 30/100) then PU Cast (poor, 15/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in PU Cast and PU Foam 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.