EPE vs HDPE
Polymer · grade comparison
EPE and HDPE are both polymer grades. HDPE is the stronger of the two: tensile strength 28 MPa (4.06 ksi) against 0.25 MPa (0.0363 ksi) for EPE, about 112 times as much. HDPE is the more ductile: elongation 600% versus 90% for EPE. EPE is lighter (0.03 g/cm³ vs 0.96 g/cm³ for HDPE) and HDPE is stiffer (1.1 GPa vs 0 GPa). On the shop floor, EPE machines more easily (excellent vs very good), HDPE welds better (excellent vs very good), and HDPE sits in a lower cost tier (budget, $) than EPE (standard, $$).
EPEChoose it when weight is the constraint, or when the part is machined in volume.
HDPEChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.
EPE vs HDPE: 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
Poisson's Ratio
Tensile Strength (Ultimate)
Elongation at Break
Compressive Strength
Compressive Modulus
Tear Strength
Compression Set (22 h, 70 °C)
Shear Modulus
Bulk Modulus
Yield Strength (0.2% offset)
Flexural Strength
Flexural Modulus
Shear Strength
Fracture Toughness (K_IC)
Izod Impact, Notched
Hardness, Shore D
Hardness, Rockwell R
Physical
Density and transition temperatures.
Density
Melting Temperature (Tm)
Water Absorption (24 h)
Water Absorption (Saturation)
Refractive Index
Same in both: Glass Transition (Tg) -110°C-166 °F
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)
Min Service Temperature
Max Service Temperature (short-term)
Heat Deflection Temp. @ 0.45 MPa
Heat Deflection Temp. @ 1.8 MPa
Vicat Softening Point (B50)
Same in both: Limiting Oxygen Index 18%
Electrical
Conductivity and insulation.
Dielectric Strength
Dielectric Constant (1 MHz)
Surface Resistivity
Comparative Tracking Index (CTI)
Same in both: Electrical Resistivity 1×10¹⁴ Ω·m3.94×10²¹ µΩ·in · Dissipation Factor (1 MHz) 3×10⁻⁴ · Volume Resistivity 1×10¹⁶ Ω·cm
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Corrosion Resistance 90 / 100 · UV / Weathering Resistance 25 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Weldability
Formability (cold)
Melt Flow Rate
Processing Melt Temperature (typ.)
Polishability
Mold Shrinkage
Mold Temperature (typ.)
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Same in both: Embodied Water 90 L/kg10.8 gal/lb · Typical Recycled Content 10%
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 | EPE | HDPE |
|---|---|---|
| CNC machining | — | Yes |
| Sheet metal | — | Yes |
| Injection molding | — | Yes |
| Default condition | — | FDA Compliant |
| Relative cost | $$ Standard | $ Budget |
| Min. machined wall | — | 0.5 mm |
| Best machined surface | — | Ra 0.8 µm |
| Chrome Plating (Plastic) | — | Yes |
| EMI Shielding Coating | — | Yes |
| Painting | — | Yes |
| Soft Touch Coating | — | Yes |
| Spray Painting | — | Yes |
| UV Coating | — | Yes |
EPE vs HDPE — frequently asked
Is HDPE stronger than EPE?
Yes. HDPE has a typical tensile strength of 28 MPa (4.06 ksi) against 0.25 MPa (0.0363 ksi) for EPE — about 112 times as much.
Which is cheaper, EPE or HDPE?
HDPE is the lower-cost material: it sits in the budget tier ($) while EPE is standard ($$). 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, EPE or HDPE?
EPE. Its machinability rates excellent (85/100) against very good (75/100) for HDPE; for welding the order is HDPE first (excellent, 95/100) then EPE (very good, 70/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in EPE and HDPE 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.