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G-3 vs XXP

Composite · grade comparison

G-3 and XXP are both composite grades. G-3 is the stronger of the two: tensile strength 250 MPa (36.3 ksi) against 83 MPa (12 ksi) for XXP, about 3.0 times as much. XXP is lighter (1.35 g/cm³ vs 1.85 g/cm³ for G-3) and G-3 is stiffer (18 GPa vs 8 GPa). On the shop floor, XXP machines more easily (very good vs fair) and XXP sits in a lower cost tier (standard, $$) than G-3 (premium, $$$).

G-3Choose it when strength drives the design.

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

G-3 vs XXP: properties

G-3XXP

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
—

Poisson's Ratio

0.17
0.25

Tensile Strength (Ultimate)

250 MPa36.3 ksi
83 MPa12 ksi

Elongation at Break

1.5%
—

Compressive Strength

310 MPa45 ksi
240 MPa34.8 ksi

Compressive Modulus

16 GPa2.3 Msi
7 GPa1 Msi

Flexural Strength

310 MPa45 ksi
117 MPa17 ksi

Flexural Modulus

18 GPa2.6 Msi
8 GPa1.2 Msi

Shear Strength

120 MPa17.4 ksi
90 MPa13.1 ksi

Izod Impact, Notched

480 J/m9 ft·lbf/in
32 J/m0.6 ft·lbf/in

Hardness, Rockwell M

110 HRM
105 HRM

Physical

Density and transition temperatures.

Density

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

Glass Transition (Tg)

160°C320 °F
155°C311 °F

Water Absorption (24 h)

1.2%
0.8%

Water Absorption (Saturation)

2.5%
3%

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
1,300 J/kg·K0.31 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

15 µm/m·K8.3 µin/in·°F
25 µm/m·K13.9 µin/in·°F

Max Service Temperature (continuous)

130°C266 °F
120°C248 °F

Min Service Temperature

-50°C-58 °F
-40°C-40 °F

Limiting Oxygen Index

40%
26%

Max Service Temperature (short-term)

180°C356 °F
155°C311 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

1×10¹⁰ Ω·m3.94×10¹⁷ µΩ·in
1×10⁹ Ω·m3.94×10¹⁶ µΩ·in

Dielectric Strength

14 kV/mm356 V/mil
20 kV/mm508 V/mil

Dielectric Constant (1 MHz)

6
4.8

Volume Resistivity

1×10¹² Ω·cm
1×10¹¹ Ω·cm

Comparative Tracking Index (CTI)

125 V
150 V

Same in both: Dissipation Factor (1 MHz) 0.04 · Surface Resistivity 1×10¹¹ Ω

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

72 / 100
55 / 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
75 / 100

Same in both: Polishability 25 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

78 MJ/kg33,534 BTU/lb
62 MJ/kg26,655 BTU/lb

Embodied Carbon (primary production)

4.5 kg CO₂/kg
3.2 kg CO₂/kg

Embodied Water

190 L/kg22.8 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)

135 kN·m/kg
61 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-3XXP
Default condition——
Relative cost$$$ Premium$$ Standard
Min. machined wall——
Best machined surface——

G-3 vs XXP — frequently asked

Is G-3 stronger than XXP?

Yes. G-3 has a typical tensile strength of 250 MPa (36.3 ksi) against 83 MPa (12 ksi) for XXP — about 3.0 times as much.

Which is cheaper, G-3 or XXP?

XXP 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 XXP?

XXP. Its machinability rates very good (75/100) against fair (42/100) for G-3.

Ready to make it?

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