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EVA Foam vs PNR

Polymer · grade comparison

EVA Foam and PNR are both polymer grades. PNR is the stronger of the two: tensile strength 8 MPa (1.16 ksi) against 1 MPa (0.145 ksi) for EVA Foam, about 8.0 times as much. PNR is the more ductile: elongation 400% versus 200% for EVA Foam. EVA Foam is lighter (0.06 g/cm³ vs 1 g/cm³ for PNR) and EVA Foam is stiffer (0.01 GPa vs 0 GPa). On the shop floor, EVA Foam machines more easily (excellent vs poor), EVA Foam welds better (very good vs not recommended), and EVA Foam sits in a lower cost tier (standard, $$) than PNR (high, $$$$).

EVA FoamChoose it when weight is the constraint, or when the part is machined in volume.

PNRChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.

EVA Foam vs PNR: properties

EVA FoamPNR

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

0.01 GPa7.25×10⁻⁴ Msi
0 GPa4.35×10⁻⁴ Msi

Poisson's Ratio

0.3
0.49

Tensile Strength (Ultimate)

1 MPa0.15 ksi
8 MPa1.2 ksi

Elongation at Break

200%
400%

Compressive Strength

0.1 MPa0.01 ksi
—

Compressive Modulus

0 GPa5.8×10⁻⁴ Msi
—

Shear Strength

0.35 MPa0.05 ksi
4 MPa0.58 ksi

Hardness, Shore A

30 Shore A
40 Shore A

Tear Strength

2 kN/m8.6 lbf/in
15 kN/m85.7 lbf/in

Compression Set (22 h, 70 °C)

15%
35%

Shear Modulus

—
0 GPa1.45×10⁻⁴ Msi

Physical

Density and transition temperatures.

Density

0.06 g/cm³0 lb/in³
1 g/cm³0.04 lb/in³

Melting Temperature (Tm)

85°C185 °F
—

Glass Transition (Tg)

-30°C-22 °F
-25°C-13 °F

Water Absorption (Saturation)

2%
—

Same in both: Water Absorption (24 h) 0.5%

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

0.04 W/m·K0.02 BTU/hr·ft·°F
0.2 W/m·K0.12 BTU/hr·ft·°F

Specific Heat Capacity

2,100 J/kg·K0.5 BTU/lb·°F
1,800 J/kg·K0.43 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

180 µm/m·K100 µin/in·°F
220 µm/m·K122 µin/in·°F

Max Service Temperature (continuous)

70°C158 °F
90°C194 °F

Min Service Temperature

-50°C-58 °F
-40°C-40 °F

Vicat Softening Point (B50)

55°C131 °F
—

Max Service Temperature (short-term)

90°C194 °F
120°C248 °F

Same in both: Limiting Oxygen Index 18%

Electrical

Conductivity and insulation.

Electrical Resistivity

1×10¹² Ω·m3.94×10¹⁹ µΩ·in
1×10¹¹ Ω·m3.94×10¹⁸ µΩ·in

Dielectric Constant (1 MHz)

1.4
3.5

Volume Resistivity

1×10¹⁴ Ω·cm
1×10¹³ Ω·cm

Surface Resistivity

1×10¹³ Ω
—

Dielectric Strength

—
18 kV/mm457 V/mil

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

90 / 100
50 / 100

Same in both: UV / Weathering Resistance 35 / 100

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

85 / 100
20 / 100

Weldability

70 / 100
10 / 100

Formability (cold)

90 / 100
85 / 100

Polishability

10 / 100
—

Mold Shrinkage

2.5%
2%

Melt Flow Rate

2.5 g/10 min
—

Processing Melt Temperature (typ.)

160°C320 °F
—

Mold Temperature (typ.)

165°C329 °F
160°C320 °F

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

75 MJ/kg32,244 BTU/lb
105 MJ/kg45,142 BTU/lb

Embodied Carbon (primary production)

3.4 kg CO₂/kg
4.5 kg CO₂/kg

Embodied Water

130 L/kg15.6 gal/lb
180 L/kg21.6 gal/lb

Typical Recycled Content

15%
0%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

17 kN·m/kg
8 kN·m/kg

Specific Stiffness (E / density)

0.1 MN·m/kg
0 MN·m/kg

Thermal Diffusivity

0.3 mm²/s
0.1 mm²/s

Thermal Shock Resistance Index

0
2

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.

0.1110100123Density (g/cm³)Yield strength (MPa) — log scaleEVA Foam

Manufacturing and finishing

CapabilityEVA FoamPNR
Injection moldingYes—
Default conditionClosed Cell—
Relative cost$$ Standard$$$$ High
Min. machined wall——
Best machined surface——
Chrome Plating (Plastic)Yes—
EMI Shielding CoatingYes—
Soft Touch CoatingYes—
Spray PaintingYes—
UV CoatingYes—

EVA Foam vs PNR — frequently asked

Is PNR stronger than EVA Foam?

Yes. PNR has a typical tensile strength of 8 MPa (1.16 ksi) against 1 MPa (0.145 ksi) for EVA Foam — about 8.0 times as much.

Which is cheaper, EVA Foam or PNR?

EVA Foam is the lower-cost material: it sits in the standard tier ($$) while PNR is high ($$$$). 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, EVA Foam or PNR?

EVA Foam. Its machinability rates excellent (85/100) against poor (20/100) for PNR; for welding the order is EVA Foam first (very good, 70/100) then PNR (not recommended, 10/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in EVA Foam and PNR 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.