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Nomex vs PBO (Zylon)

Composite · grade comparison

Nomex and PBO (Zylon) are both composite grades. PBO (Zylon) is the stronger of the two: tensile strength 5,800 MPa (841 ksi) against 90 MPa (13.1 ksi) for Nomex, about 64 times as much. In exchange, Nomex is the more ductile: elongation 12% versus 3.5% for PBO (Zylon). Nomex is lighter (1.1 g/cm³ vs 1.54 g/cm³ for PBO (Zylon)) and PBO (Zylon) is stiffer (180 GPa vs 2.5 GPa). On the shop floor, Nomex machines more easily (fair vs poor).

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

PBO (Zylon)Choose it when strength drives the design, or when the part sees heat.

Nomex vs PBO (Zylon): properties

NomexPBO (Zylon)

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

2.5 GPa0.36 Msi
180 GPa26.1 Msi

Tensile Strength (Ultimate)

90 MPa13.1 ksi
5,800 MPa841 ksi

Elongation at Break

12%
3.5%

Tear Strength

20 kN/m114 lbf/in
—

Compressive Strength

—
300 MPa43.5 ksi

Physical

Density and transition temperatures.

Density

1.1 g/cm³0.04 lb/in³
1.54 g/cm³0.06 lb/in³

Glass Transition (Tg)

275°C527 °F
500°C932 °F

Water Absorption (24 h)

4.5%
2%

Water Absorption (Saturation)

9%
2.5%

Thermal

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

Thermal Conductivity

0.13 W/m·K0.08 BTU/hr·ft·°F
—

Thermal Expansion (CTE, 20–100 °C)

17 µm/m·K9.4 µin/in·°F
-6 µm/m·K-3.3 µin/in·°F

Max Service Temperature (continuous)

220°C428 °F
300°C572 °F

Min Service Temperature

-70°C-94 °F
-196°C-321 °F

Limiting Oxygen Index

28%
68%

Max Service Temperature (short-term)

300°C572 °F
550°C1,022 °F

Same in both: Specific Heat Capacity 1,200 J/kg·K0.29 BTU/lb·°F

Electrical

Conductivity and insulation.

Electrical Resistivity

1×10¹⁴ Ω·m3.94×10²¹ µΩ·in
—

Dielectric Strength

30 kV/mm762 V/mil
—

Dielectric Constant (1 MHz)

2.7
—

Dissipation Factor (1 MHz)

0.008
—

Volume Resistivity

1×10¹⁶ Ω·cm
1×10¹⁴ Ω·cm

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

UV / Weathering Resistance

25 / 100
12 / 100

Same in both: Corrosion Resistance 70 / 100

Manufacturability

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

Machinability

50 / 100
15 / 100

Polishability

10 / 100
—

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

260 MJ/kg111,780 BTU/lb
500 MJ/kg214,962 BTU/lb

Embodied Carbon (primary production)

11 kg CO₂/kg
30 kg CO₂/kg

Embodied Water

400 L/kg47.9 gal/lb
—

Same in both: Typical Recycled Content 0%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

82 kN·m/kg
3,766 kN·m/kg

Specific Stiffness (E / density)

2.3 MN·m/kg
116.9 MN·m/kg

Strength versus weight

Yield strength against density for every composite grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.

1101001,000510Density (g/cm³)Yield strength (MPa) — log scale

Manufacturing and finishing

CapabilityNomexPBO (Zylon)
Default condition——
Relative cost$$$$ High$$$$ High
Min. machined wall——
Best machined surface——

Nomex vs PBO (Zylon) — frequently asked

Is PBO (Zylon) stronger than Nomex?

Yes. PBO (Zylon) has a typical tensile strength of 5,800 MPa (841 ksi) against 90 MPa (13.1 ksi) for Nomex — about 64 times as much.

Which is cheaper, Nomex or PBO (Zylon)?

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

Which is easier to machine, Nomex or PBO (Zylon)?

Nomex. Its machinability rates fair (50/100) against poor (15/100) for PBO (Zylon).

Ready to make it?

Upload a CAD file and FabDigit prices the part in Nomex and PBO (Zylon) 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.