FabDigit

Nomex vs Kevlar 29 vs Kevlar 49 vs Kevlar 149

Benchmark · 4 materials

Side-by-side benchmark of 4 composite grades.

Nomex vs Kevlar 29 and 2 more: properties

NomexKevlar 29Kevlar 49Kevlar 149

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

2.5 GPa0.36 Msi
70.5 GPa10.2 Msi
112 GPa16.2 Msi
175 GPa25.4 Msi

Tensile Strength (Ultimate)

90 MPa13.1 ksi
2,920 MPa424 ksi
3,000 MPa435 ksi
3,400 MPa493 ksi

Elongation at Break

12%
3.6%
2.4%
1.5%

Tear Strength

20 kN/m114 lbf/in

Shear Modulus

2.2 GPa0.32 Msi
2.9 GPa0.42 Msi
2 GPa0.29 Msi

Poisson's Ratio

0.36
0.36
0.36

Compressive Strength

400 MPa58 ksi
400 MPa58 ksi

Physical

Density and transition temperatures.

Density

1.1 g/cm³0.04 lb/in³
1.44 g/cm³0.05 lb/in³
1.44 g/cm³0.05 lb/in³
1.47 g/cm³0.05 lb/in³

Glass Transition (Tg)

275°C527 °F
360°C680 °F
360°C680 °F
360°C680 °F

Water Absorption (24 h)

4.5%
4%
1%

Water Absorption (Saturation)

9%
7%
4%
1.5%

Thermal

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

Thermal Conductivity

0.13 W/m·K0.08 BTU/hr·ft·°F
0.04 W/m·K0.02 BTU/hr·ft·°F
0.04 W/m·K0.02 BTU/hr·ft·°F
0.05 W/m·K0.03 BTU/hr·ft·°F

Specific Heat Capacity

1,200 J/kg·K0.29 BTU/lb·°F
1,420 J/kg·K0.34 BTU/lb·°F
1,420 J/kg·K0.34 BTU/lb·°F
1,420 J/kg·K0.34 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

17 µm/m·K9.4 µin/in·°F
-2 µm/m·K-1.1 µin/in·°F
-2 µm/m·K-1.1 µin/in·°F
-4 µm/m·K-2.2 µin/in·°F

Max Service Temperature (continuous)

220°C428 °F
180°C356 °F
160°C320 °F
180°C356 °F

Min Service Temperature

-70°C-94 °F
-196°C-321 °F
-196°C-321 °F
-196°C-321 °F

Limiting Oxygen Index

28%
29%
29%
29%

Max Service Temperature (short-term)

300°C572 °F
250°C482 °F
250°C482 °F
300°C572 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

1×10¹⁴ Ω·m3.94×10²¹ µΩ·in
1×10¹³ Ω·m3.94×10²⁰ µΩ·in
1×10¹³ Ω·m3.94×10²⁰ µΩ·in
1×10¹³ Ω·m3.94×10²⁰ µΩ·in

Dielectric Strength

30 kV/mm762 V/mil

Dielectric Constant (1 MHz)

2.7
4
4
4

Dissipation Factor (1 MHz)

0.008
0.02
0.02
0.01

Volume Resistivity

1×10¹⁶ Ω·cm
1×10¹⁵ Ω·cm
1×10¹⁵ Ω·cm
1×10¹⁵ Ω·cm

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

70 / 100
65 / 100
70 / 100
65 / 100

UV / Weathering Resistance

25 / 100
20 / 100
20 / 100
25 / 100

Manufacturability

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

Machinability

50 / 100
25 / 100
25 / 100
25 / 100

Polishability

10 / 100
20 / 100
25 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

260 MJ/kg111,780 BTU/lb
270 MJ/kg116,079 BTU/lb
280 MJ/kg120,378 BTU/lb
285 MJ/kg122,528 BTU/lb

Embodied Carbon (primary production)

11 kg CO₂/kg
13 kg CO₂/kg
17 kg CO₂/kg
16 kg CO₂/kg

Embodied Water

400 L/kg47.9 gal/lb
500 L/kg59.9 gal/lb
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
2,028 kN·m/kg
2,083 kN·m/kg
2,313 kN·m/kg

Specific Stiffness (E / density)

2.3 MN·m/kg
49 MN·m/kg
77.8 MN·m/kg
119 MN·m/kg

Thermal Diffusivity

0.1 mm²/s
0 mm²/s
0 mm²/s
0 mm²/s

Thermal Shock Resistance Index

0
-1
-1
0

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

CapabilityNomexKevlar 29Kevlar 49Kevlar 149
Default condition
Relative cost$$$$ High$$$$ High$$$$ High$$$$ High
Min. machined wall
Best machined surface

Ready to make it?

Upload a CAD file and FabDigit prices the part in Nomex and Kevlar 29 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.