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PEN vs PETG

Polymer · grade comparison

PEN and PETG are both polymer grades. PEN is the stronger of the two: yield strength 78 MPa (11.3 ksi) against 50 MPa (7.25 ksi) for PETG, about 56% more; tensile strength follows at 80 MPa (11.6 ksi) vs 50 MPa (7.25 ksi). In exchange, PETG is the more ductile: elongation 120% versus 40% for PEN, and PEN is harder (85 Shore D vs 78 Shore D). PETG is lighter (1.27 g/cm³ vs 1.36 g/cm³ for PEN) and PEN is stiffer (2.8 GPa vs 2.1 GPa). On the shop floor, PETG welds better (very good vs good) and PETG sits in a lower cost tier (budget, $) than PEN (high, $$$$).

PENChoose it when strength drives the design, or when the part sees heat.

PETGChoose it when the part is bent, formed or impact-loaded, or when weight is the constraint.

PEN vs PETG: properties

PENPETG

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

2.8 GPa0.41 Msi
2.1 GPa0.3 Msi

Shear Modulus

1 GPa0.15 Msi
0.77 GPa0.11 Msi

Bulk Modulus

4 GPa0.62 Msi
—

Poisson's Ratio

0.39
0.4

Tensile Strength (Ultimate)

80 MPa11.6 ksi
50 MPa7.3 ksi

Yield Strength (0.2% offset)

78 MPa11.3 ksi
50 MPa7.3 ksi

Elongation at Break

40%
120%

Compressive Strength

100 MPa14.5 ksi
60 MPa8.7 ksi

Compressive Modulus

2.9 GPa0.42 Msi
—

Flexural Strength

115 MPa16.7 ksi
70 MPa10.2 ksi

Flexural Modulus

2.9 GPa0.42 Msi
2.1 GPa0.3 Msi

Shear Strength

55 MPa8 ksi
—

Fracture Toughness (K_IC)

3.5 MPa·√m3.2 ksi·√in
—

Izod Impact, Notched

45 J/m0.84 ft·lbf/in
95 J/m1.8 ft·lbf/in

Hardness, Shore D

85 Shore D
78 Shore D

Hardness, Rockwell M

95 HRM
—

Hardness, Rockwell R

120 HRR
115 HRR

Physical

Density and transition temperatures.

Density

1.36 g/cm³0.05 lb/in³
1.27 g/cm³0.05 lb/in³

Melting Temperature (Tm)

268°C514 °F
—

Glass Transition (Tg)

122°C252 °F
80°C176 °F

Water Absorption (24 h)

0.25%
0.13%

Water Absorption (Saturation)

0.6%
0.5%

Refractive Index

1.64
1.57

Light Transmission

85%
89%

Thermal

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

Thermal Conductivity

0.24 W/m·K0.14 BTU/hr·ft·°F
0.2 W/m·K0.12 BTU/hr·ft·°F

Specific Heat Capacity

1,250 J/kg·K0.3 BTU/lb·°F
1,200 J/kg·K0.29 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

60 µm/m·K33.3 µin/in·°F
68 µm/m·K37.8 µin/in·°F

Max Service Temperature (continuous)

155°C311 °F
63°C145 °F

Min Service Temperature

-70°C-94 °F
-40°C-40 °F

Heat Deflection Temp. @ 0.45 MPa

155°C311 °F
70°C158 °F

Heat Deflection Temp. @ 1.8 MPa

110°C230 °F
64°C147 °F

Vicat Softening Point (B50)

130°C266 °F
82°C180 °F

Limiting Oxygen Index

26%
23%

Max Service Temperature (short-term)

220°C428 °F
75°C167 °F

Electrical

Conductivity and insulation.

Dielectric Strength

30 kV/mm762 V/mil
16 kV/mm406 V/mil

Dielectric Constant (1 MHz)

3
2.8

Dissipation Factor (1 MHz)

0.01
0.02

Surface Resistivity

1×10¹⁵ Ω
1×10¹⁶ Ω

Comparative Tracking Index (CTI)

600 V
—

Same in both: Electrical Resistivity 1×10¹⁴ Ω·m3.94×10²¹ µΩ·in · Volume Resistivity 1×10¹⁶ Ω·cm

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

76 / 100
85 / 100

UV / Weathering Resistance

80 / 100
45 / 100

Manufacturability

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

Machinability

60 / 100
65 / 100

Weldability

60 / 100
80 / 100

Formability (cold)

45 / 100
88 / 100

Polishability

70 / 100
72 / 100

Mold Shrinkage

1.2%
0.35%

Processing Melt Temperature (typ.)

300°C572 °F
245°C473 °F

Mold Temperature (typ.)

120°C248 °F
25°C77 °F

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

110 MJ/kg47,292 BTU/lb
84 MJ/kg36,114 BTU/lb

Embodied Carbon (primary production)

5.5 kg CO₂/kg
3.2 kg CO₂/kg

Embodied Water

90 L/kg10.8 gal/lb
210 L/kg25.2 gal/lb

Same in both: Typical Recycled Content 0%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

59 kN·m/kg
39 kN·m/kg

Specific Stiffness (E / density)

2.1 MN·m/kg
1.7 MN·m/kg

Modulus of Resilience

1,086 kJ/m³
595 kJ/m³

Same in both: Thermal Diffusivity 0.1 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 scalePETGPEN

Manufacturing and finishing

CapabilityPENPETG
CNC machining—Yes
Sheet metal—Yes
Injection molding—Yes
3D printing—Yes
Default condition—Unfilled
Relative cost$$$$ High$ Budget
Min. machined wall—0.5 mm
Best machined surface—Ra 0.8 µm
Chrome Plating (Plastic)—Yes
Conductive Coating—Yes
Dyeing (Nylon)—Yes
EMI Shielding Coating—Yes
Painting—Yes
Primer Coating—Yes
Soft Touch Coating—Yes
Spray Painting—Yes
Tinted Coating—Yes
UV Coating—Yes
Vacuum Metallization—Yes
Waterproof Coating—Yes

PEN vs PETG — frequently asked

Is PEN stronger than PETG?

Yes. PEN has a typical yield strength of 78 MPa (11.3 ksi) against 50 MPa (7.25 ksi) for PETG — about 56% more. Tensile strength is 80 MPa (11.6 ksi) vs 50 MPa (7.25 ksi).

Which is cheaper, PEN or PETG?

PETG is the lower-cost material: it sits in the budget tier ($) while PEN is high ($$$$). 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, PEN or PETG?

PETG, by a small margin. Both rate good for machinability — 65/100 against 60/100 for PEN; for welding the order is PETG first (very good, 80/100) then PEN (good, 60/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in PEN and PETG 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.