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DAP vs EPN

Polymer · grade comparison

DAP and EPN are both polymer grades. EPN is the stronger of the two: tensile strength 72 MPa (10.4 ksi) against 55 MPa (7.98 ksi) for DAP, about 31% more. EPN is the more ductile: elongation 2% versus 0.6% for DAP. EPN is lighter (1.21 g/cm³ vs 1.8 g/cm³ for DAP) and DAP is stiffer (10.5 GPa vs 3.3 GPa). On the shop floor, EPN machines more easily (good vs fair) and EPN sits in a lower cost tier (premium, $$$) than DAP (high, $$$$).

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

DAP vs EPN: properties

DAPEPN

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

10.5 GPa1.5 Msi
3.3 GPa0.48 Msi

Poisson's Ratio

0.32
0.36

Tensile Strength (Ultimate)

55 MPa8 ksi
72 MPa10.4 ksi

Elongation at Break

0.6%
2%

Compressive Strength

200 MPa29 ksi
155 MPa22.5 ksi

Flexural Strength

105 MPa15.2 ksi
120 MPa17.4 ksi

Flexural Modulus

11 GPa1.6 Msi
3.4 GPa0.49 Msi

Izod Impact, Notched

40 J/m0.75 ft·lbf/in
18 J/m0.34 ft·lbf/in

Hardness, Rockwell M

110 HRM
108 HRM

Shear Modulus

—
1.3 GPa0.18 Msi

Bulk Modulus

—
4 GPa0.61 Msi

Compressive Modulus

—
3.2 GPa0.46 Msi

Shear Strength

—
55 MPa8 ksi

Fracture Toughness (K_IC)

—
0.55 MPa·√m0.5 ksi·√in

Hardness, Shore D

—
88 Shore D

Physical

Density and transition temperatures.

Density

1.8 g/cm³0.07 lb/in³
1.21 g/cm³0.04 lb/in³

Glass Transition (Tg)

160°C320 °F
175°C347 °F

Water Absorption (24 h)

0.2%
0.15%

Water Absorption (Saturation)

0.6%
1.6%

Refractive Index

—
1.59

Thermal

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

Thermal Conductivity

0.5 W/m·K0.29 BTU/hr·ft·°F
0.2 W/m·K0.12 BTU/hr·ft·°F

Specific Heat Capacity

1,050 J/kg·K0.25 BTU/lb·°F
1,100 J/kg·K0.26 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

25 µm/m·K13.9 µin/in·°F
60 µm/m·K33.3 µin/in·°F

Max Service Temperature (continuous)

180°C356 °F
170°C338 °F

Min Service Temperature

-60°C-76 °F
-55°C-67 °F

Heat Deflection Temp. @ 0.45 MPa

285°C545 °F
190°C374 °F

Heat Deflection Temp. @ 1.8 MPa

265°C509 °F
168°C334 °F

Limiting Oxygen Index

32%
23%

Max Service Temperature (short-term)

230°C446 °F
220°C428 °F

Electrical

Conductivity and insulation.

Dielectric Strength

16 kV/mm406 V/mil
19 kV/mm483 V/mil

Dielectric Constant (1 MHz)

4.3
3.8

Dissipation Factor (1 MHz)

0.011
0.02

Surface Resistivity

1×10¹⁴ Ω
1×10¹⁵ Ω

Comparative Tracking Index (CTI)

200 V
250 V

Same in both: Electrical Resistivity 1×10¹³ Ω·m3.94×10²⁰ µΩ·in · Volume Resistivity 1×10¹⁵ Ω·cm

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

80 / 100
88 / 100

UV / Weathering Resistance

55 / 100
22 / 100

Manufacturability

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

Machinability

40 / 100
55 / 100

Weldability

0 / 100
—

Formability (cold)

0 / 100
—

Polishability

45 / 100
70 / 100

Mold Shrinkage

0.4%
1.2%

Mold Temperature (typ.)

160°C320 °F
165°C329 °F

Processing Melt Temperature (typ.)

—
100°C212 °F

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

105 MJ/kg45,142 BTU/lb
135 MJ/kg58,040 BTU/lb

Embodied Carbon (primary production)

5.5 kg CO₂/kg
6.8 kg CO₂/kg

Embodied Water

—
250 L/kg30 gal/lb

Same in both: Typical Recycled Content 0%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

31 kN·m/kg
60 kN·m/kg

Specific Stiffness (E / density)

5.8 MN·m/kg
2.7 MN·m/kg

Thermal Diffusivity

0.3 mm²/s
0.2 mm²/s

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.

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

Manufacturing and finishing

CapabilityDAPEPN
Default condition——
Relative cost$$$$ High$$$ Premium
Min. machined wall——
Best machined surface——

DAP vs EPN — frequently asked

Is EPN stronger than DAP?

Yes. EPN has a typical tensile strength of 72 MPa (10.4 ksi) against 55 MPa (7.98 ksi) for DAP — about 31% more.

Which is cheaper, DAP or EPN?

EPN is the lower-cost material: it sits in the premium tier ($$$) while DAP is high ($$$$). 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, DAP or EPN?

EPN. Its machinability rates good (55/100) against fair (40/100) for DAP.

Ready to make it?

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