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CPE vs UHMW-PE

Polymer · grade comparison

CPE and UHMW-PE are both polymer grades. UHMW-PE is the stronger of the two: tensile strength 40 MPa (5.8 ksi) against 8 MPa (1.16 ksi) for CPE, about 5.0 times as much. In exchange, CPE is the more ductile: elongation 700% versus 350% for UHMW-PE, and UHMW-PE is harder (64 Shore D vs 18 Shore D). UHMW-PE is lighter (0.94 g/cm³ vs 1.16 g/cm³ for CPE) and UHMW-PE is stiffer (0.72 GPa vs 0.02 GPa). On the shop floor, UHMW-PE machines more easily (very good vs poor), CPE welds better (very good vs poor), and CPE sits in a lower cost tier (budget, $) than UHMW-PE (standard, $$).

CPEChoose 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 weight is the constraint.

CPE vs UHMW-PE: properties

CPEUHMW-PE

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

0.02 GPa0 Msi
0.72 GPa0.1 Msi

Poisson's Ratio

0.47
0.46

Tensile Strength (Ultimate)

8 MPa1.2 ksi
40 MPa5.8 ksi

Elongation at Break

700%
350%

Hardness, Shore A

65 Shore A
—

Hardness, Shore D

18 Shore D
64 Shore D

Tear Strength

28 kN/m160 lbf/in
—

Compression Set (22 h, 70 °C)

38%
—

Shear Modulus

—
0.25 GPa0.04 Msi

Yield Strength (0.2% offset)

—
21 MPa3 ksi

Compressive Strength

—
20 MPa2.9 ksi

Compressive Modulus

—
0.6 GPa0.09 Msi

Flexural Strength

—
25 MPa3.6 ksi

Flexural Modulus

—
0.75 GPa0.11 Msi

Shear Strength

—
22 MPa3.2 ksi

Fracture Toughness (K_IC)

—
3.5 MPa·√m3.2 ksi·√in

Izod Impact, Notched

—
1,300 J/m24.3 ft·lbf/in

Hardness, Rockwell R

—
50 HRR

Physical

Density and transition temperatures.

Density

1.16 g/cm³0.04 lb/in³
0.94 g/cm³0.03 lb/in³

Glass Transition (Tg)

-20°C-4 °F
-120°C-184 °F

Water Absorption (24 h)

0.1%
0.01%

Melting Temperature (Tm)

—
135°C275 °F

Water Absorption (Saturation)

—
0.01%

Refractive Index

—
1.51

Thermal

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

Thermal Conductivity

0.2 W/m·K0.12 BTU/hr·ft·°F
0.41 W/m·K0.24 BTU/hr·ft·°F

Specific Heat Capacity

1,800 J/kg·K0.43 BTU/lb·°F
1,840 J/kg·K0.44 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

170 µm/m·K94.4 µin/in·°F
200 µm/m·K111 µin/in·°F

Max Service Temperature (continuous)

120°C248 °F
80°C176 °F

Min Service Temperature

-30°C-22 °F
-200°C-328 °F

Limiting Oxygen Index

26%
17%

Max Service Temperature (short-term)

150°C302 °F
110°C230 °F

Heat Deflection Temp. @ 0.45 MPa

—
80°C176 °F

Heat Deflection Temp. @ 1.8 MPa

—
44°C111 °F

Vicat Softening Point (B50)

—
80°C176 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

1×10¹² Ω·m3.94×10¹⁹ µΩ·in
1×10¹³ Ω·m3.94×10²⁰ µΩ·in

Dielectric Strength

22 kV/mm559 V/mil
30 kV/mm762 V/mil

Dielectric Constant (1 MHz)

5
2.3

Dissipation Factor (1 MHz)

0.04
3×10⁻⁴

Volume Resistivity

1×10¹⁴ Ω·cm
1×10¹⁵ Ω·cm

Surface Resistivity

—
1×10¹⁴ Ω

Comparative Tracking Index (CTI)

—
600 V

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

85 / 100
90 / 100

UV / Weathering Resistance

88 / 100
30 / 100

Manufacturability

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

Machinability

25 / 100
75 / 100

Weldability

70 / 100
15 / 100

Formability (cold)

90 / 100
55 / 100

Polishability

20 / 100
25 / 100

Mold Shrinkage

1.9%
3%

Processing Melt Temperature (typ.)

175°C347 °F
200°C392 °F

Mold Temperature (typ.)

170°C338 °F
—

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

75 MJ/kg32,244 BTU/lb
85 MJ/kg36,543 BTU/lb

Embodied Carbon (primary production)

2.8 kg CO₂/kg
3.2 kg CO₂/kg

Embodied Water

—
100 L/kg12 gal/lb

Same in both: Typical Recycled Content 0%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

7 kN·m/kg
43 kN·m/kg

Specific Stiffness (E / density)

0 MN·m/kg
0.8 MN·m/kg

Thermal Diffusivity

0.1 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 scaleUHMW-PE

Manufacturing and finishing

CapabilityCPEUHMW-PE
CNC machining—Yes
Sheet metal—Yes
Injection molding—Yes
Default condition—FDA
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

CPE vs UHMW-PE — frequently asked

Is UHMW-PE stronger than CPE?

Yes. UHMW-PE has a typical tensile strength of 40 MPa (5.8 ksi) against 8 MPa (1.16 ksi) for CPE — about 5.0 times as much.

Which is cheaper, CPE or UHMW-PE?

CPE is the lower-cost material: it sits in the budget tier ($) while UHMW-PE 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, CPE or UHMW-PE?

UHMW-PE. Its machinability rates very good (75/100) against poor (25/100) for CPE; for welding the order is CPE first (very good, 70/100) then UHMW-PE (poor, 15/100).

Ready to make it?

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