PEX vs UHMW-PE
Polymer · grade comparison
PEX and UHMW-PE are both polymer grades. UHMW-PE is the stronger of the two: yield strength 21 MPa (3.05 ksi) against 17 MPa (2.47 ksi) for PEX, about 24% more; tensile strength follows at 40 MPa (5.8 ksi) vs 22 MPa (3.19 ksi). In exchange, PEX is the more ductile: elongation 500% versus 350% for UHMW-PE, and UHMW-PE is harder (64 Shore D vs 60 Shore D). UHMW-PE is stiffer (0.72 GPa vs 0.68 GPa) and PEX runs hotter in service (95°C vs 80°C continuous). On the shop floor, UHMW-PE machines more easily (very good vs fair).
PEXChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
UHMW-PEChoose it when strength drives the design, or when the part is machined in volume.
PEX vs UHMW-PE: 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)
Yield Strength (0.2% offset)
Elongation at Break
Compressive Strength
Flexural Strength
Flexural Modulus
Shear Strength
Izod Impact, Notched
Hardness, Shore A
Hardness, Shore D
Hardness, Rockwell R
Tear Strength
Shear Modulus
Compressive Modulus
Same in both: Fracture Toughness (K_IC) 3.5 MPa·√m3.2 ksi·√in
Physical
Density and transition temperatures.
Density
Melting Temperature (Tm)
Water Absorption (Saturation)
Refractive Index
Same in both: Glass Transition (Tg) -120°C-184 °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)
Limiting Oxygen Index
Same in both: Max Service Temperature (short-term) 110°C230 °F
Electrical
Conductivity and insulation.
Electrical Resistivity
Dielectric Strength
Dissipation Factor (1 MHz)
Volume Resistivity
Surface Resistivity
Same in both: Dielectric Constant (1 MHz) 2.3 · Comparative Tracking Index (CTI) 600 V
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
UV / Weathering Resistance
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Weldability
Formability (cold)
Mold Shrinkage
Melt Flow Rate
Processing Melt Temperature (typ.)
Mold Temperature (typ.)
Same in both: Polishability 25 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Same in both: Typical Recycled Content 0%
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Modulus of Resilience
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.
Manufacturing and finishing
| Capability | PEX | UHMW-PE |
|---|---|---|
| CNC machining | — | Yes |
| Sheet metal | — | Yes |
| Injection molding | — | Yes |
| Default condition | — | FDA |
| Relative cost | $$ Standard | $$ 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 |
PEX vs UHMW-PE — frequently asked
Is UHMW-PE stronger than PEX?
Yes. UHMW-PE has a typical yield strength of 21 MPa (3.05 ksi) against 17 MPa (2.47 ksi) for PEX — about 24% more. Tensile strength is 40 MPa (5.8 ksi) vs 22 MPa (3.19 ksi).
Which is cheaper, PEX or UHMW-PE?
Both sit in the same relative cost tier ($$, standard); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which is easier to machine, PEX or UHMW-PE?
UHMW-PE. Its machinability rates very good (75/100) against fair (42/100) for PEX; for welding the order is UHMW-PE first (poor, 15/100) then PEX (not recommended, 10/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in PEX and UHMW-PE 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.