HDPE vs PEX
Polymer · grade comparison
HDPE and PEX are both polymer grades. HDPE is the stronger of the two: yield strength 26 MPa (3.77 ksi) against 17 MPa (2.47 ksi) for PEX, about 53% more; tensile strength follows at 28 MPa (4.06 ksi) vs 22 MPa (3.19 ksi). HDPE is the more ductile: elongation 600% versus 500% for PEX, and HDPE is harder (65 Shore D vs 60 Shore D). HDPE is stiffer (1.1 GPa vs 0.68 GPa) and PEX runs hotter in service (95°C vs 80°C continuous). On the shop floor, HDPE machines more easily (very good vs fair), HDPE welds better (excellent vs not recommended), and HDPE sits in a lower cost tier (budget, $) than PEX (standard, $$).
HDPEChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.
PEXChoose it when the part sees heat.
HDPE vs PEX: 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
Shear Modulus
Bulk Modulus
Poisson's Ratio
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Compressive Strength
Compressive Modulus
Flexural Strength
Flexural Modulus
Shear Strength
Fracture Toughness (K_IC)
Izod Impact, Notched
Hardness, Shore D
Hardness, Rockwell R
Hardness, Shore A
Tear Strength
Physical
Density and transition temperatures.
Density
Glass Transition (Tg)
Water Absorption (Saturation)
Refractive Index
Same in both: Melting Temperature (Tm) 132°C270 °F · Water Absorption (24 h) 0.01%
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
Heat Deflection Temp. @ 0.45 MPa
Heat Deflection Temp. @ 1.8 MPa
Vicat Softening Point (B50)
Same in both: Limiting Oxygen Index 18% · Max Service Temperature (short-term) 110°C230 °F
Electrical
Conductivity and insulation.
Dielectric Strength
Dielectric Constant (1 MHz)
Dissipation Factor (1 MHz)
Same in both: Electrical Resistivity 1×10¹⁴ Ω·m3.94×10²¹ µΩ·in · Volume Resistivity 1×10¹⁶ Ω·cm · Surface Resistivity 1×10¹⁵ Ω · Comparative Tracking Index (CTI) 600 V
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: UV / Weathering Resistance 25 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Weldability
Formability (cold)
Polishability
Mold Shrinkage
Melt Flow Rate
Processing Melt Temperature (typ.)
Mold Temperature (typ.)
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Typical Recycled Content
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Modulus of Resilience
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 | HDPE | PEX |
|---|---|---|
| CNC machining | Yes | — |
| Sheet metal | Yes | — |
| Injection molding | Yes | — |
| Default condition | FDA Compliant | — |
| Relative cost | $ Budget | $$ Standard |
| 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 | — |
HDPE vs PEX — frequently asked
Is HDPE stronger than PEX?
Yes. HDPE has a typical yield strength of 26 MPa (3.77 ksi) against 17 MPa (2.47 ksi) for PEX — about 53% more. Tensile strength is 28 MPa (4.06 ksi) vs 22 MPa (3.19 ksi).
Which is cheaper, HDPE or PEX?
HDPE is the lower-cost material: it sits in the budget tier ($) while PEX 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, HDPE or PEX?
HDPE. Its machinability rates very good (75/100) against fair (42/100) for PEX; for welding the order is HDPE first (excellent, 95/100) then PEX (not recommended, 10/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in HDPE and PEX 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.