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EPP vs PP-H

Polymer · grade comparison

EPP and PP-H are both polymer grades. PP-H is the stronger of the two: tensile strength 35 MPa (5.08 ksi) against 0.4 MPa (0.058 ksi) for EPP, about 88 times as much. PP-H is the more ductile: elongation 300% versus 18% for EPP. EPP is lighter (0.03 g/cm³ vs 0.91 g/cm³ for PP-H) and PP-H is stiffer (1.5 GPa vs 0 GPa). On the shop floor, PP-H welds better (excellent vs good) and PP-H sits in a lower cost tier (budget, $) than EPP (premium, $$$).

EPPChoose it when weight is the constraint.

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

EPP vs PP-H: properties

EPPPP-H

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

0 GPa5.8×10⁻⁴ Msi
1.5 GPa0.22 Msi

Poisson's Ratio

0.05
0.42

Tensile Strength (Ultimate)

0.4 MPa0.06 ksi
35 MPa5.1 ksi

Elongation at Break

18%
300%

Compressive Strength

0.22 MPa0.03 ksi
45 MPa6.5 ksi

Compressive Modulus

0 GPa4.35×10⁻⁴ Msi
1.5 GPa0.22 Msi

Flexural Strength

0.45 MPa0.07 ksi
45 MPa6.5 ksi

Flexural Modulus

0.01 GPa8.7×10⁻⁴ Msi
1.5 GPa0.22 Msi

Shear Strength

0.2 MPa0.03 ksi
25 MPa3.6 ksi

Compression Set (22 h, 70 °C)

12%
—

Shear Modulus

—
0.5 GPa0.07 Msi

Bulk Modulus

—
4 GPa0.51 Msi

Yield Strength (0.2% offset)

—
34 MPa4.9 ksi

Fracture Toughness (K_IC)

—
3 MPa·√m2.7 ksi·√in

Izod Impact, Notched

—
30 J/m0.56 ft·lbf/in

Hardness, Shore D

—
72 Shore D

Hardness, Rockwell M

—
68 HRM

Hardness, Rockwell R

—
96 HRR

Physical

Density and transition temperatures.

Density

0.03 g/cm³0 lb/in³
0.91 g/cm³0.03 lb/in³

Melting Temperature (Tm)

155°C311 °F
165°C329 °F

Glass Transition (Tg)

-12°C10 °F
-10°C14 °F

Water Absorption (24 h)

0.6%
0.01%

Water Absorption (Saturation)

2%
0.03%

Refractive Index

—
1.49

Thermal

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

Thermal Conductivity

0.04 W/m·K0.02 BTU/hr·ft·°F
0.22 W/m·K0.13 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

90 µm/m·K50 µin/in·°F
110 µm/m·K61.1 µin/in·°F

Min Service Temperature

-40°C-40 °F
-10°C14 °F

Limiting Oxygen Index

18%
18%

Heat Deflection Temp. @ 0.45 MPa

—
100°C212 °F

Heat Deflection Temp. @ 1.8 MPa

—
60°C140 °F

Vicat Softening Point (B50)

—
90°C194 °F

Same in both: Specific Heat Capacity 1,900 J/kg·K0.45 BTU/lb·°F · Max Service Temperature (continuous) 100°C212 °F · Max Service Temperature (short-term) 130°C266 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

1×10¹³ Ω·m3.94×10²⁰ µΩ·in
1×10¹⁵ Ω·m3.94×10²² µΩ·in

Dielectric Constant (1 MHz)

1.08
2.25

Dissipation Factor (1 MHz)

4×10⁻⁴
3×10⁻⁴

Volume Resistivity

1×10¹⁵ Ω·cm
1×10¹⁷ Ω·cm

Surface Resistivity

1×10¹⁴ Ω
1×10¹⁵ Ω

Dielectric Strength

—
28 kV/mm711 V/mil

Comparative Tracking Index (CTI)

—
600 V

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

UV / Weathering Resistance

25 / 100
20 / 100

Same in both: Corrosion Resistance 90 / 100

Manufacturability

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

Machinability

60 / 100
65 / 100

Weldability

55 / 100
90 / 100

Formability (cold)

35 / 100
65 / 100

Mold Shrinkage

2.5%
1.6%

Polishability

—
30 / 100

Melt Flow Rate

—
12 g/10 min

Processing Melt Temperature (typ.)

—
230°C446 °F

Mold Temperature (typ.)

—
35°C95 °F

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

100 MJ/kg42,992 BTU/lb
78 MJ/kg33,534 BTU/lb

Embodied Carbon (primary production)

3.8 kg CO₂/kg
2 kg CO₂/kg

Embodied Water

130 L/kg15.6 gal/lb
100 L/kg12 gal/lb

Typical Recycled Content

10%
3%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

13 kN·m/kg
39 kN·m/kg

Specific Stiffness (E / density)

0.1 MN·m/kg
1.7 MN·m/kg

Thermal Diffusivity

0.6 mm²/s
0.1 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 scalePP-H

Manufacturing and finishing

CapabilityEPPPP-H
Default condition——
Relative cost$$$ Premium$ Budget
Min. machined wall——
Best machined surface——

EPP vs PP-H — frequently asked

Is PP-H stronger than EPP?

Yes. PP-H has a typical tensile strength of 35 MPa (5.08 ksi) against 0.4 MPa (0.058 ksi) for EPP — about 88 times as much.

Which is cheaper, EPP or PP-H?

PP-H is the lower-cost material: it sits in the budget tier ($) while EPP is premium ($$$). 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, EPP or PP-H?

PP-H, by a small margin. Both rate good for machinability — 65/100 against 60/100 for EPP; for welding the order is PP-H first (excellent, 90/100) then EPP (good, 55/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in EPP and PP-H 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.