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G-3 vs XXX

Composite · grade comparison

G-3 and XXX are both composite grades. G-3 is the stronger of the two: tensile strength 250 MPa (36.3 ksi) against 110 MPa (16 ksi) for XXX, about 127% more. G-3 is the more ductile: elongation 1.5% versus 1.3% for XXX. XXX is lighter (1.36 g/cm³ vs 1.85 g/cm³ for G-3) and G-3 is stiffer (18 GPa vs 8 GPa). On the shop floor, XXX machines more easily (good vs fair) and XXX sits in a lower cost tier (standard, $$) than G-3 (premium, $$$).

G-3Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.

XXXChoose it when weight is the constraint, or when the part is machined in volume.

G-3 vs XXX: properties

G-3XXX

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

18 GPa2.6 Msi
8 GPa1.2 Msi

Shear Modulus

6.5 GPa0.94 Msi
3 GPa0.44 Msi

Poisson's Ratio

0.17
0.3

Tensile Strength (Ultimate)

250 MPa36.3 ksi
110 MPa16 ksi

Elongation at Break

1.5%
1.3%

Compressive Strength

310 MPa45 ksi
240 MPa34.8 ksi

Compressive Modulus

16 GPa2.3 Msi
7 GPa1 Msi

Flexural Strength

310 MPa45 ksi
125 MPa18.1 ksi

Flexural Modulus

18 GPa2.6 Msi
8.5 GPa1.2 Msi

Shear Strength

120 MPa17.4 ksi
100 MPa14.5 ksi

Izod Impact, Notched

480 J/m9 ft·lbf/in
45 J/m0.84 ft·lbf/in

Hardness, Rockwell M

110 HRM
105 HRM

Fracture Toughness (K_IC)

—
1.6 MPa·√m1.5 ksi·√in

Physical

Density and transition temperatures.

Density

1.85 g/cm³0.07 lb/in³
1.36 g/cm³0.05 lb/in³

Glass Transition (Tg)

160°C320 °F
—

Water Absorption (24 h)

1.2%
0.7%

Same in both: Water Absorption (Saturation) 2.5%

Thermal

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

Thermal Conductivity

0.3 W/m·K0.17 BTU/hr·ft·°F
0.25 W/m·K0.14 BTU/hr·ft·°F

Specific Heat Capacity

1,150 J/kg·K0.27 BTU/lb·°F
1,400 J/kg·K0.33 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

15 µm/m·K8.3 µin/in·°F
22 µm/m·K12.2 µin/in·°F

Max Service Temperature (continuous)

130°C266 °F
120°C248 °F

Min Service Temperature

-50°C-58 °F
-60°C-76 °F

Limiting Oxygen Index

40%
27%

Max Service Temperature (short-term)

180°C356 °F
150°C302 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

1×10¹⁰ Ω·m3.94×10¹⁷ µΩ·in
1×10¹¹ Ω·m3.94×10¹⁸ µΩ·in

Dielectric Strength

14 kV/mm356 V/mil
15 kV/mm381 V/mil

Dielectric Constant (1 MHz)

6
4.2

Dissipation Factor (1 MHz)

0.04
0.038

Volume Resistivity

1×10¹² Ω·cm
1×10¹³ Ω·cm

Surface Resistivity

1×10¹¹ Ω
1×10¹² Ω

Same in both: Comparative Tracking Index (CTI) 125 V

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

72 / 100
60 / 100

Same in both: UV / Weathering Resistance 30 / 100

Manufacturability

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

Machinability

42 / 100
60 / 100

Same in both: Polishability 25 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

78 MJ/kg33,534 BTU/lb
95 MJ/kg40,843 BTU/lb

Embodied Water

190 L/kg22.8 gal/lb
—

Same in both: Embodied Carbon (primary production) 4.5 kg CO₂/kg · Typical Recycled Content 0%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

135 kN·m/kg
81 kN·m/kg

Specific Stiffness (E / density)

9.7 MN·m/kg
5.9 MN·m/kg

Same in both: Thermal Diffusivity 0.1 mm²/s · 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

CapabilityG-3XXX
Default condition——
Relative cost$$$ Premium$$ Standard
Min. machined wall——
Best machined surface——

G-3 vs XXX — frequently asked

Is G-3 stronger than XXX?

Yes. G-3 has a typical tensile strength of 250 MPa (36.3 ksi) against 110 MPa (16 ksi) for XXX — about 127% more.

Which is cheaper, G-3 or XXX?

XXX is the lower-cost material: it sits in the standard tier ($$) while G-3 is premium ($$$). 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, G-3 or XXX?

XXX. Its machinability rates good (60/100) against fair (42/100) for G-3.

Ready to make it?

Upload a CAD file and FabDigit prices the part in G-3 and XXX 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.