HR Foam vs RIM PU Foam
Polymer · grade comparison
HR Foam and RIM PU Foam are both polymer grades. RIM PU Foam is the stronger of the two: tensile strength 12 MPa (1.74 ksi) against 0.13 MPa (0.0189 ksi) for HR Foam, about 92 times as much. HR Foam is lighter (0.05 g/cm³ vs 0.6 g/cm³ for RIM PU Foam) and RIM PU Foam is stiffer (0.22 GPa vs 2×10⁻⁵ GPa). On the shop floor, HR Foam machines more easily (excellent vs good), HR Foam welds better (fair vs not recommended), and HR Foam forms better (excellent vs poor).
HR FoamChoose it when weight is the constraint, or when the part is machined in volume.
RIM PU FoamChoose it when strength drives the design.
HR Foam vs RIM 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
Poisson's Ratio
Tensile Strength (Ultimate)
Compressive Strength
Compressive Modulus
Tear Strength
Compression Set (22 h, 70 °C)
Yield Strength (0.2% offset)
Flexural Strength
Flexural Modulus
Shear Strength
Izod Impact, Notched
Hardness, Shore A
Hardness, Shore D
Same in both: Elongation at Break 130%
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
Max Service Temperature (continuous)
Limiting Oxygen Index
Max Service Temperature (short-term)
Thermal Expansion (CTE, 20–100 °C)
Heat Deflection Temp. @ 0.45 MPa
Heat Deflection Temp. @ 1.8 MPa
Same in both: Min Service Temperature -40°C-40 °F
Electrical
Conductivity and insulation.
Dielectric Strength
Dielectric Constant (1 MHz)
Dissipation Factor (1 MHz)
Surface Resistivity
Comparative Tracking Index (CTI)
Same in both: Electrical Resistivity 1×10¹⁰ Ω·m3.94×10¹⁷ µΩ·in · Volume Resistivity 1×10¹² 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
Weldability
Formability (cold)
Polishability
Mold Shrinkage
Processing Melt Temperature (typ.)
Mold Temperature (typ.)
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Typical Recycled Content
Same in both: Embodied Water 250 L/kg30 gal/lb
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Thermal Diffusivity
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 | HR Foam | RIM PU Foam |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$ Standard | $$ Standard |
| Min. machined wall | — | — |
| Best machined surface | — | — |
HR Foam vs RIM PU Foam — frequently asked
Is RIM PU Foam stronger than HR Foam?
Yes. RIM PU Foam has a typical tensile strength of 12 MPa (1.74 ksi) against 0.13 MPa (0.0189 ksi) for HR Foam — about 92 times as much.
Which is cheaper, HR Foam or RIM PU Foam?
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, HR Foam or RIM PU Foam?
HR Foam. Its machinability rates excellent (85/100) against good (55/100) for RIM PU Foam; for welding the order is HR Foam first (fair, 40/100) then RIM PU Foam (not recommended, 10/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in HR Foam and RIM 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.