PETG vs PU Foam
Polymer · grade comparison
PETG and PU Foam are both polymer grades, both multipurpose plastic. PETG is the stronger of the two: tensile strength 50 MPa (7.25 ksi) against 0.13 MPa (0.0189 ksi) for PU Foam, about 385 times as much. In exchange, PU Foam is the more ductile: elongation 150% versus 120% for PETG. PU Foam is lighter (0.03 g/cm³ vs 1.27 g/cm³ for PETG) and PETG is stiffer (2.1 GPa vs 2×10⁻⁴ GPa). On the shop floor, PU Foam machines more easily (excellent vs good) and PETG welds better (very good vs poor).
PETGChoose it when strength drives the design, or when it will be welded.
PU FoamChoose it when the part is bent, formed or impact-loaded, or when weight is the constraint.
PETG 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
Poisson's Ratio
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Compressive Strength
Flexural Strength
Flexural Modulus
Izod Impact, Notched
Hardness, Shore D
Hardness, Rockwell R
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
Light Transmission
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)
Heat Deflection Temp. @ 0.45 MPa
Heat Deflection Temp. @ 1.8 MPa
Vicat Softening Point (B50)
Limiting Oxygen Index
Max Service Temperature (short-term)
Same in both: Min Service Temperature -40°C-40 °F
Electrical
Conductivity and insulation.
Electrical Resistivity
Dielectric Strength
Dielectric Constant (1 MHz)
Dissipation Factor (1 MHz)
Volume Resistivity
Surface 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
Mold Shrinkage
Processing Melt Temperature (typ.)
Mold Temperature (typ.)
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)
Thermal Diffusivity
Same in both: Thermal Shock Resistance Index 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 | PETG | PU Foam |
|---|---|---|
| CNC machining | Yes | — |
| Sheet metal | Yes | — |
| 3D printing | Yes | — |
| Default condition | Unfilled | Open Cell |
| Relative cost | $ Budget | $ Budget |
| 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.
PETG vs PU Foam — frequently asked
Is PETG stronger than PU Foam?
Yes. PETG has a typical tensile strength of 50 MPa (7.25 ksi) against 0.13 MPa (0.0189 ksi) for PU Foam — about 385 times as much.
Which is cheaper, PETG or PU Foam?
Both sit in the same relative cost tier ($, budget); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which is easier to machine, PETG or PU Foam?
PU Foam. Its machinability rates excellent (90/100) against good (65/100) for PETG; for welding the order is PETG first (very good, 80/100) then PU Foam (poor, 30/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in PETG 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.