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EPN vs Epoxy

Polymer · grade comparison

EPN and Epoxy are both polymer grades. EPN is the stronger of the two: tensile strength 72 MPa (10.4 ksi) against 65 MPa (9.43 ksi) for Epoxy, about 11% more. In exchange, Epoxy is the more ductile: elongation 4% versus 2% for EPN. EPN is stiffer (3.3 GPa vs 3 GPa) and EPN runs hotter in service (170°C vs 130°C continuous). On the shop floor, Epoxy sits in a lower cost tier (standard, $$) than EPN (premium, $$$).

EPNChoose it when strength drives the design, or when the part sees heat.

EpoxyChoose it when the part is bent, formed or impact-loaded, or when cost is the deciding factor.

EPN vs Epoxy: properties

EPNEpoxy

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

3.3 GPa0.48 Msi
3 GPa0.44 Msi

Shear Modulus

1.3 GPa0.18 Msi
1.2 GPa0.17 Msi

Bulk Modulus

4 GPa0.61 Msi
5 GPa0.65 Msi

Poisson's Ratio

0.36
0.35

Tensile Strength (Ultimate)

72 MPa10.4 ksi
65 MPa9.4 ksi

Elongation at Break

2%
4%

Compressive Strength

155 MPa22.5 ksi
110 MPa16 ksi

Compressive Modulus

3.2 GPa0.46 Msi
3 GPa0.44 Msi

Flexural Strength

120 MPa17.4 ksi
110 MPa16 ksi

Flexural Modulus

3.4 GPa0.49 Msi
3 GPa0.44 Msi

Shear Strength

55 MPa8 ksi
45 MPa6.5 ksi

Fracture Toughness (K_IC)

0.55 MPa·√m0.5 ksi·√in
0.6 MPa·√m0.55 ksi·√in

Izod Impact, Notched

18 J/m0.34 ft·lbf/in
20 J/m0.37 ft·lbf/in

Hardness, Shore D

88 Shore D
85 Shore D

Hardness, Rockwell M

108 HRM
100 HRM

Physical

Density and transition temperatures.

Density

1.21 g/cm³0.04 lb/in³
1.2 g/cm³0.04 lb/in³

Glass Transition (Tg)

175°C347 °F
120°C248 °F

Refractive Index

1.59
1.56

Light Transmission

—
88%

Same in both: Water Absorption (24 h) 0.15% · Water Absorption (Saturation) 1.6%

Thermal

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

Max Service Temperature (continuous)

170°C338 °F
130°C266 °F

Min Service Temperature

-55°C-67 °F
-50°C-58 °F

Heat Deflection Temp. @ 0.45 MPa

190°C374 °F
130°C266 °F

Heat Deflection Temp. @ 1.8 MPa

168°C334 °F
110°C230 °F

Limiting Oxygen Index

23%
20%

Max Service Temperature (short-term)

220°C428 °F
180°C356 °F

Same in both: Thermal Conductivity 0.2 W/m·K0.12 BTU/hr·ft·°F · Specific Heat Capacity 1,100 J/kg·K0.26 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 60 µm/m·K33.3 µin/in·°F

Electrical

Conductivity and insulation.

Dielectric Strength

19 kV/mm483 V/mil
20 kV/mm508 V/mil

Dielectric Constant (1 MHz)

3.8
3.6

Surface Resistivity

1×10¹⁵ Ω
1×10¹⁴ Ω

Comparative Tracking Index (CTI)

250 V
300 V

Same in both: Electrical Resistivity 1×10¹³ Ω·m3.94×10²⁰ µΩ·in · Dissipation Factor (1 MHz) 0.02 · Volume Resistivity 1×10¹⁵ Ω·cm

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

88 / 100
82 / 100

UV / Weathering Resistance

22 / 100
25 / 100

Manufacturability

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

Polishability

70 / 100
75 / 100

Mold Shrinkage

1.2%
0.2%

Processing Melt Temperature (typ.)

100°C212 °F
—

Weldability

—
0 / 100

Formability (cold)

—
5 / 100

Same in both: Machinability 55 / 100 · Mold Temperature (typ.) 165°C329 °F

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

135 MJ/kg58,040 BTU/lb
137 MJ/kg58,899 BTU/lb

Embodied Carbon (primary production)

6.8 kg CO₂/kg
6.6 kg CO₂/kg

Embodied Water

250 L/kg30 gal/lb
190 L/kg22.8 gal/lb

Same in both: Typical Recycled Content 0%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

60 kN·m/kg
54 kN·m/kg

Specific Stiffness (E / density)

2.7 MN·m/kg
2.5 MN·m/kg

Same in both: Thermal Diffusivity 0.2 mm²/s · 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.

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

Manufacturing and finishing

CapabilityEPNEpoxy
Default condition——
Relative cost$$$ Premium$$ Standard
Min. machined wall——
Best machined surface——

EPN vs Epoxy — frequently asked

Is EPN stronger than Epoxy?

Yes. EPN has a typical tensile strength of 72 MPa (10.4 ksi) against 65 MPa (9.43 ksi) for Epoxy — about 11% more.

Which is cheaper, EPN or Epoxy?

Epoxy is the lower-cost material: it sits in the standard tier ($$) while EPN is premium ($$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.

When should I choose EPN over Epoxy?

Pick EPN when strength drives the design, or when the part sees heat. Pick Epoxy when the part is bent, formed or impact-loaded, or when cost is the deciding factor.

Ready to make it?

Upload a CAD file and FabDigit prices the part in EPN and Epoxy 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.