Polyurea vs RPU
Polyurethane · grade comparison
Polyurea and RPU are both polyurethane grades. RPU is the stronger of the two: tensile strength 55 MPa (7.98 ksi) against 18 MPa (2.61 ksi) for Polyurea, about 3.1 times as much. In exchange, Polyurea is the more ductile: elongation 380% versus 6% for RPU, and RPU is harder (80 Shore D vs 50 Shore D). Polyurea is lighter (1.05 g/cm³ vs 1.15 g/cm³ for RPU) and RPU is stiffer (2.4 GPa vs 0.06 GPa). On the shop floor, RPU machines more easily (excellent vs poor) and RPU sits in a lower cost tier (standard, $$) than Polyurea (premium, $$$).
PolyureaChoose it when the part is bent, formed or impact-loaded, or when weight is the constraint.
RPUChoose it when strength drives the design, or when the part is machined in volume.
Polyurea vs RPU: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all polyurethane 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 polyurethane 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
Poisson's Ratio
Tensile Strength (Ultimate)
Elongation at Break
Compressive Strength
Flexural Modulus
Shear Strength
Hardness, Shore A
Hardness, Shore D
Tear Strength
Compression Set (22 h, 70 °C)
Shear Modulus
Bulk Modulus
Compressive Modulus
Flexural Strength
Fracture Toughness (K_IC)
Izod Impact, Notched
Hardness, Rockwell M
Hardness, Rockwell R
Physical
Density and transition temperatures.
Density
Glass Transition (Tg)
Water Absorption (24 h)
Water Absorption (Saturation)
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
Max Service Temperature (short-term)
Heat Deflection Temp. @ 0.45 MPa
Heat Deflection Temp. @ 1.8 MPa
Same in both: Limiting Oxygen Index 22%
Electrical
Conductivity and insulation.
Dielectric Strength
Dissipation Factor (1 MHz)
Surface Resistivity
Comparative Tracking Index (CTI)
Same in both: Electrical Resistivity 1×10¹¹ Ω·m3.94×10¹⁸ µΩ·in · Dielectric Constant (1 MHz) 4 · Volume Resistivity 1×10¹³ Ω·cm
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
Polishability
Formability (cold)
Mold Shrinkage
Processing Melt Temperature (typ.)
Mold Temperature (typ.)
Same in both: Weldability 5 / 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)
Specific Stiffness (E / density)
Same in both: Thermal Diffusivity 0.1 mm²/s · Thermal Shock Resistance Index 0
Strength versus weight
Yield strength against density for every polyurethane grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
Manufacturing and finishing
| Capability | Polyurea | RPU |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$$ Premium | $$ Standard |
| Min. machined wall | — | — |
| Best machined surface | — | — |
Polyurea vs RPU — frequently asked
Is RPU stronger than Polyurea?
Yes. RPU has a typical tensile strength of 55 MPa (7.98 ksi) against 18 MPa (2.61 ksi) for Polyurea — about 3.1 times as much.
Which is cheaper, Polyurea or RPU?
RPU is the lower-cost material: it sits in the standard tier ($$) while Polyurea is premium ($$$). 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, Polyurea or RPU?
RPU. Its machinability rates excellent (85/100) against poor (25/100) for Polyurea.
Ready to make it?
Upload a CAD file and FabDigit prices the part in Polyurea and RPU 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.