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HDPE vs HMWPE

Polymer · grade comparison

HDPE and HMWPE are both polymer grades. HDPE is the stronger of the two: yield strength 26 MPa (3.77 ksi) against 24 MPa (3.48 ksi) for HMWPE, about 8% more. In exchange, HMWPE is the more ductile: elongation 700% versus 600% for HDPE. HDPE is stiffer (1.1 GPa vs 0.95 GPa). On the shop floor, HDPE machines more easily (very good vs good).

HDPEChoose it when strength drives the design, or when the part is machined in volume.

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

HDPE vs HMWPE: properties

HDPEHMWPE

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

1.1 GPa0.16 Msi
0.95 GPa0.14 Msi

Shear Modulus

0.4 GPa0.06 Msi
0.35 GPa0.05 Msi

Bulk Modulus

3 GPa0.44 Msi
3 GPa0.38 Msi

Tensile Strength (Ultimate)

28 MPa4.1 ksi
30 MPa4.4 ksi

Yield Strength (0.2% offset)

26 MPa3.8 ksi
24 MPa3.5 ksi

Elongation at Break

600%
700%

Flexural Strength

27 MPa3.9 ksi
26 MPa3.8 ksi

Flexural Modulus

1.2 GPa0.17 Msi
1.1 GPa0.15 Msi

Fracture Toughness (K_IC)

2 MPa·√m1.8 ksi·√in
2.8 MPa·√m2.5 ksi·√in

Izod Impact, Notched

90 J/m1.7 ft·lbf/in
250 J/m4.7 ft·lbf/in

Hardness, Rockwell R

55 HRR
50 HRR

Same in both: Poisson's Ratio 0.44 · Compressive Strength 22 MPa3.2 ksi · Compressive Modulus 0.9 GPa0.13 Msi · Shear Strength 20 MPa2.9 ksi · Hardness, Shore D 65 Shore D

Physical

Density and transition temperatures.

Density

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

Melting Temperature (Tm)

132°C270 °F
133°C271 °F

Glass Transition (Tg)

-110°C-166 °F
-120°C-184 °F

Water Absorption (Saturation)

0.05%
0.02%

Same in both: Water Absorption (24 h) 0.01% · Refractive Index 1.54

Thermal

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

Thermal Conductivity

0.48 W/m·K0.28 BTU/hr·ft·°F
0.45 W/m·K0.26 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

150 µm/m·K83.3 µin/in·°F
160 µm/m·K88.9 µin/in·°F

Min Service Temperature

-80°C-112 °F
-100°C-148 °F

Heat Deflection Temp. @ 0.45 MPa

76°C169 °F
77°C171 °F

Heat Deflection Temp. @ 1.8 MPa

47°C117 °F
46°C115 °F

Vicat Softening Point (B50)

76°C169 °F
125°C257 °F

Limiting Oxygen Index

18%
17%

Same in both: Specific Heat Capacity 1,900 J/kg·K0.45 BTU/lb·°F · Max Service Temperature (continuous) 80°C176 °F · Max Service Temperature (short-term) 110°C230 °F

Electrical

Conductivity and insulation.

Dielectric Constant (1 MHz)

2.35
2.3

Same in both: Electrical Resistivity 1×10¹⁴ Ω·m3.94×10²¹ µΩ·in · Dielectric Strength 24 kV/mm610 V/mil · Dissipation Factor (1 MHz) 3×10⁻⁴ · 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

90 / 100
93 / 100

Same in both: UV / Weathering Resistance 25 / 100

Manufacturability

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

Machinability

75 / 100
62 / 100

Weldability

95 / 100
92 / 100

Formability (cold)

70 / 100
78 / 100

Polishability

30 / 100
25 / 100

Mold Shrinkage

2%
2.5%

Melt Flow Rate

8 g/10 min
0.1 g/10 min

Processing Melt Temperature (typ.)

230°C446 °F
215°C419 °F

Mold Temperature (typ.)

40°C104 °F
35°C95 °F

Sustainability

Primary-production footprint per kilogram.

Embodied Carbon (primary production)

2 kg CO₂/kg
2.1 kg CO₂/kg

Embodied Water

90 L/kg10.8 gal/lb
110 L/kg13.2 gal/lb

Same in both: Embodied Energy (primary production) 78 MJ/kg33,534 BTU/lb · Typical Recycled Content 10%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

29 kN·m/kg
32 kN·m/kg

Specific Stiffness (E / density)

1.2 MN·m/kg
1 MN·m/kg

Modulus of Resilience

307 kJ/m³
303 kJ/m³

Thermal Diffusivity

0.3 mm²/s
0.2 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 scaleHDPEHMWPE

Manufacturing and finishing

CapabilityHDPEHMWPE
CNC machiningYes—
Sheet metalYes—
Injection moldingYes—
Default conditionFDA Compliant—
Relative cost$ Budget$ Budget
Min. machined wall0.5 mm—
Best machined surfaceRa 0.8 µm—
Chrome Plating (Plastic)Yes—
EMI Shielding CoatingYes—
PaintingYes—
Soft Touch CoatingYes—
Spray PaintingYes—
UV CoatingYes—

HDPE vs HMWPE — frequently asked

Is HDPE stronger than HMWPE?

Yes. HDPE has a typical yield strength of 26 MPa (3.77 ksi) against 24 MPa (3.48 ksi) for HMWPE — about 8% more. Tensile strength is 28 MPa (4.06 ksi) vs 30 MPa (4.35 ksi).

Which is cheaper, HDPE or HMWPE?

Both sit in the same relative cost tier ($, budget); the part price will be decided by machining time, tolerance and quantity rather than by the material.

Which is easier to machine, HDPE or HMWPE?

HDPE. Its machinability rates very good (75/100) against good (62/100) for HMWPE.

Ready to make it?

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