Phenolic Foam vs PI Foam
Polymer · grade comparison
Phenolic Foam and PI Foam are both polymer grades. Phenolic Foam is the stronger of the two: tensile strength 0.15 MPa (0.0218 ksi) against 0.06 MPa (0.0087 ksi) for PI Foam, about 150% more. In exchange, PI Foam is the more ductile: elongation 15% versus 2% for Phenolic Foam. Phenolic Foam is stiffer (0.01 GPa vs 3×10⁻⁴ GPa) and PI Foam runs hotter in service (300°C vs 150°C continuous). On the shop floor, Phenolic Foam machines more easily (excellent vs good) and Phenolic Foam sits in a lower cost tier (standard, $$) than PI Foam (high, $$$$).
Phenolic FoamChoose it when strength drives the design, or when the part is machined in volume.
PI FoamChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
Phenolic Foam vs PI 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)
Elongation at Break
Compressive Strength
Compressive Modulus
Flexural Strength
Flexural Modulus
Shear Strength
Tear Strength
Compression Set (22 h, 70 °C)
Physical
Density and transition temperatures.
Density
Water Absorption (24 h)
Water Absorption (Saturation)
Glass Transition (Tg)
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)
Electrical
Conductivity and insulation.
Electrical Resistivity
Dielectric Constant (1 MHz)
Dielectric Strength
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)
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Same in both: Typical Recycled Content 0%
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 | Phenolic Foam | PI Foam |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$ Standard | $$$$ High |
| Min. machined wall | — | — |
| Best machined surface | — | — |
Phenolic Foam vs PI Foam — frequently asked
Is Phenolic Foam stronger than PI Foam?
Yes. Phenolic Foam has a typical tensile strength of 0.15 MPa (0.0218 ksi) against 0.06 MPa (0.0087 ksi) for PI Foam — about 150% more.
Which is cheaper, Phenolic Foam or PI Foam?
Phenolic Foam is the lower-cost material: it sits in the standard tier ($$) while PI Foam is high ($$$$). 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, Phenolic Foam or PI Foam?
Phenolic Foam. Its machinability rates excellent (90/100) against good (55/100) for PI Foam.
Ready to make it?
Upload a CAD file and FabDigit prices the part in Phenolic Foam and PI 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.