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3240 vs G-9

Composite · grade comparison

3240 and G-9 are both composite grades. 3240 is the stronger of the two: tensile strength 300 MPa (43.5 ksi) against 240 MPa (34.8 ksi) for G-9, about 25% more. 3240 is stiffer (21 GPa vs 19 GPa) and G-9 runs hotter in service (155°C vs 130°C continuous). On the shop floor, 3240 machines more easily (fair vs poor) and 3240 sits in a lower cost tier (premium, $$$) than G-9 (high, $$$$).

3240Choose it when strength drives the design, or when the part is machined in volume.

G-9Choose it when the part sees heat.

3240 vs G-9: properties

3240G-9

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

21 GPa3 Msi
19 GPa2.8 Msi

Shear Modulus

6 GPa0.87 Msi
—

Poisson's Ratio

0.14
0.16

Tensile Strength (Ultimate)

300 MPa43.5 ksi
240 MPa34.8 ksi

Elongation at Break

1.8%
—

Compressive Strength

400 MPa58 ksi
345 MPa50 ksi

Compressive Modulus

18 GPa2.6 Msi
15 GPa2.2 Msi

Flexural Strength

400 MPa58 ksi
310 MPa45 ksi

Flexural Modulus

22 GPa3.2 Msi
18 GPa2.6 Msi

Shear Strength

125 MPa18.1 ksi
120 MPa17.4 ksi

Izod Impact, Notched

500 J/m9.4 ft·lbf/in
400 J/m7.5 ft·lbf/in

Hardness, Rockwell M

108 HRM
115 HRM

Physical

Density and transition temperatures.

Density

1.9 g/cm³0.07 lb/in³
1.95 g/cm³0.07 lb/in³

Glass Transition (Tg)

125°C257 °F
—

Water Absorption (24 h)

0.15%
0.8%

Water Absorption (Saturation)

0.55%
1.8%

Thermal

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

Thermal Conductivity

0.35 W/m·K0.2 BTU/hr·ft·°F
0.32 W/m·K0.18 BTU/hr·ft·°F

Max Service Temperature (continuous)

130°C266 °F
155°C311 °F

Limiting Oxygen Index

24%
42%

Max Service Temperature (short-term)

180°C356 °F
200°C392 °F

Same in both: Specific Heat Capacity 1,100 J/kg·K0.26 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 14 µm/m·K7.8 µin/in·°F · Min Service Temperature -60°C-76 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

1×10¹² Ω·m3.94×10¹⁹ µΩ·in
1×10¹¹ Ω·m3.94×10¹⁸ µΩ·in

Dielectric Strength

18 kV/mm457 V/mil
12 kV/mm305 V/mil

Dielectric Constant (1 MHz)

5.2
6.5

Dissipation Factor (1 MHz)

0.022
0.03

Volume Resistivity

1×10¹⁴ Ω·cm
1×10¹³ Ω·cm

Surface Resistivity

1×10¹³ Ω
1×10¹² Ω

Comparative Tracking Index (CTI)

200 V
600 V

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

85 / 100
70 / 100

UV / Weathering Resistance

40 / 100
45 / 100

Manufacturability

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

Machinability

45 / 100
30 / 100

Polishability

30 / 100
20 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

110 MJ/kg47,292 BTU/lb
100 MJ/kg42,992 BTU/lb

Embodied Carbon (primary production)

6.5 kg CO₂/kg
6 kg CO₂/kg

Embodied Water

180 L/kg21.6 gal/lb
200 L/kg24 gal/lb

Same in both: Typical Recycled Content 0%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

158 kN·m/kg
123 kN·m/kg

Specific Stiffness (E / density)

11.1 MN·m/kg
9.7 MN·m/kg

Thermal Diffusivity

0.2 mm²/s
0.1 mm²/s

Same in both: Thermal Shock Resistance Index 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

Capability3240G-9
Default condition——
Relative cost$$$ Premium$$$$ High
Min. machined wall——
Best machined surface——

3240 vs G-9 — frequently asked

Is 3240 stronger than G-9?

Yes. 3240 has a typical tensile strength of 300 MPa (43.5 ksi) against 240 MPa (34.8 ksi) for G-9 — about 25% more.

Which is cheaper, 3240 or G-9?

3240 is the lower-cost material: it sits in the premium tier ($$$) while G-9 is high ($$$$). 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, 3240 or G-9?

3240. Its machinability rates fair (45/100) against poor (30/100) for G-9.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 3240 and G-9 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.