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HMWPE vs PEX

Polymer · grade comparison

HMWPE and PEX are both polymer grades. HMWPE is the stronger of the two: yield strength 24 MPa (3.48 ksi) against 17 MPa (2.47 ksi) for PEX, about 41% more; tensile strength follows at 30 MPa (4.35 ksi) vs 22 MPa (3.19 ksi). HMWPE is the more ductile: elongation 700% versus 500% for PEX, and HMWPE is harder (65 Shore D vs 60 Shore D). HMWPE is stiffer (0.95 GPa vs 0.68 GPa) and PEX runs hotter in service (95°C vs 80°C continuous). On the shop floor, HMWPE machines more easily (good vs fair), HMWPE welds better (excellent vs not recommended), and HMWPE sits in a lower cost tier (budget, $) than PEX (standard, $$).

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

PEXChoose it when the part sees heat.

HMWPE vs PEX: properties

HMWPEPEX

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

0.95 GPa0.14 Msi
0.68 GPa0.1 Msi

Shear Modulus

0.35 GPa0.05 Msi
—

Bulk Modulus

3 GPa0.38 Msi
—

Poisson's Ratio

0.44
0.45

Tensile Strength (Ultimate)

30 MPa4.4 ksi
22 MPa3.2 ksi

Yield Strength (0.2% offset)

24 MPa3.5 ksi
17 MPa2.5 ksi

Elongation at Break

700%
500%

Compressive Strength

22 MPa3.2 ksi
18 MPa2.6 ksi

Compressive Modulus

0.9 GPa0.13 Msi
—

Flexural Strength

26 MPa3.8 ksi
17 MPa2.5 ksi

Flexural Modulus

1.1 GPa0.15 Msi
0.63 GPa0.09 Msi

Shear Strength

20 MPa2.9 ksi
14 MPa2 ksi

Fracture Toughness (K_IC)

2.8 MPa·√m2.5 ksi·√in
3.5 MPa·√m3.2 ksi·√in

Izod Impact, Notched

250 J/m4.7 ft·lbf/in
300 J/m5.6 ft·lbf/in

Hardness, Shore D

65 Shore D
60 Shore D

Hardness, Rockwell R

50 HRR
42 HRR

Hardness, Shore A

—
95 Shore A

Tear Strength

—
95 kN/m542 lbf/in

Physical

Density and transition temperatures.

Density

0.95 g/cm³0.03 lb/in³
0.94 g/cm³0.03 lb/in³

Melting Temperature (Tm)

133°C271 °F
132°C270 °F

Water Absorption (Saturation)

0.02%
0.03%

Refractive Index

1.54
—

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

0.45 W/m·K0.26 BTU/hr·ft·°F
0.38 W/m·K0.22 BTU/hr·ft·°F

Specific Heat Capacity

1,900 J/kg·K0.45 BTU/lb·°F
2,300 J/kg·K0.55 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

160 µm/m·K88.9 µin/in·°F
170 µm/m·K94.4 µin/in·°F

Max Service Temperature (continuous)

80°C176 °F
95°C203 °F

Min Service Temperature

-100°C-148 °F
-40°C-40 °F

Heat Deflection Temp. @ 0.45 MPa

77°C171 °F
70°C158 °F

Heat Deflection Temp. @ 1.8 MPa

46°C115 °F
42°C108 °F

Vicat Softening Point (B50)

125°C257 °F
98°C208 °F

Limiting Oxygen Index

17%
18%

Same in both: Max Service Temperature (short-term) 110°C230 °F

Electrical

Conductivity and insulation.

Dielectric Strength

24 kV/mm610 V/mil
25 kV/mm635 V/mil

Dissipation Factor (1 MHz)

3×10⁻⁴
4×10⁻⁴

Same in both: Electrical Resistivity 1×10¹⁴ Ω·m3.94×10²¹ µΩ·in · Dielectric Constant (1 MHz) 2.3 · 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

93 / 100
92 / 100

Same in both: UV / Weathering Resistance 25 / 100

Manufacturability

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

Machinability

62 / 100
42 / 100

Weldability

92 / 100
10 / 100

Formability (cold)

78 / 100
90 / 100

Melt Flow Rate

0.1 g/10 min
1 g/10 min

Mold Temperature (typ.)

35°C95 °F
60°C140 °F

Same in both: Polishability 25 / 100 · Mold Shrinkage 2.5% · Processing Melt Temperature (typ.) 215°C419 °F

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

78 MJ/kg33,534 BTU/lb
82 MJ/kg35,254 BTU/lb

Embodied Carbon (primary production)

2.1 kg CO₂/kg
2.3 kg CO₂/kg

Embodied Water

110 L/kg13.2 gal/lb
120 L/kg14.4 gal/lb

Typical Recycled Content

10%
0%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

32 kN·m/kg
23 kN·m/kg

Specific Stiffness (E / density)

1 MN·m/kg
0.7 MN·m/kg

Modulus of Resilience

303 kJ/m³
213 kJ/m³

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.

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

Manufacturing and finishing

CapabilityHMWPEPEX
Default condition——
Relative cost$ Budget$$ Standard
Min. machined wall——
Best machined surface——

HMWPE vs PEX — frequently asked

Is HMWPE stronger than PEX?

Yes. HMWPE has a typical yield strength of 24 MPa (3.48 ksi) against 17 MPa (2.47 ksi) for PEX — about 41% more. Tensile strength is 30 MPa (4.35 ksi) vs 22 MPa (3.19 ksi).

Which is cheaper, HMWPE or PEX?

HMWPE 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, HMWPE or PEX?

HMWPE. Its machinability rates good (62/100) against fair (42/100) for PEX; for welding the order is HMWPE first (excellent, 92/100) then PEX (not recommended, 10/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in HMWPE 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.