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G-3 vs XXXP

Composite · grade comparison

G-3 and XXXP are both composite grades. G-3 is the stronger of the two: tensile strength 250 MPa (36.3 ksi) against 105 MPa (15.2 ksi) for XXXP, about 138% more. G-3 is the more ductile: elongation 1.5% versus 1.2% for XXXP. XXXP is lighter (1.35 g/cm³ vs 1.85 g/cm³ for G-3) and G-3 is stiffer (18 GPa vs 9 GPa). On the shop floor, XXXP machines more easily (excellent vs fair) and XXXP 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.

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

G-3 vs XXXP: properties

G-3XXXP

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

18 GPa2.6 Msi
9 GPa1.3 Msi

Shear Modulus

6.5 GPa0.94 Msi
—

Poisson's Ratio

0.17
0.3

Tensile Strength (Ultimate)

250 MPa36.3 ksi
105 MPa15.2 ksi

Elongation at Break

1.5%
1.2%

Compressive Strength

310 MPa45 ksi
240 MPa34.8 ksi

Compressive Modulus

16 GPa2.3 Msi
8 GPa1.2 Msi

Flexural Strength

310 MPa45 ksi
120 MPa17.4 ksi

Flexural Modulus

18 GPa2.6 Msi
9.5 GPa1.4 Msi

Shear Strength

120 MPa17.4 ksi
90 MPa13.1 ksi

Izod Impact, Notched

480 J/m9 ft·lbf/in
30 J/m0.56 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
150°C302 °F

Water Absorption (24 h)

1.2%
0.85%

Water Absorption (Saturation)

2.5%
2%

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
25 µm/m·K13.9 µin/in·°F

Max Service Temperature (continuous)

130°C266 °F
125°C257 °F

Limiting Oxygen Index

40%
28%

Max Service Temperature (short-term)

180°C356 °F
160°C320 °F

Same in both: Min Service Temperature -50°C-58 °F

Electrical

Conductivity and insulation.

Dielectric Strength

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

Dielectric Constant (1 MHz)

6
4.3

Dissipation Factor (1 MHz)

0.04
0.038

Surface Resistivity

1×10¹¹ Ω
1×10¹² Ω

Comparative Tracking Index (CTI)

125 V
175 V

Same in both: Electrical Resistivity 1×10¹⁰ Ω·m3.94×10¹⁷ µΩ·in · Volume Resistivity 1×10¹² Ω·cm

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
85 / 100

Polishability

25 / 100
35 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

78 MJ/kg33,534 BTU/lb
75 MJ/kg32,244 BTU/lb

Embodied Carbon (primary production)

4.5 kg CO₂/kg
4 kg CO₂/kg

Embodied Water

190 L/kg22.8 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
78 kN·m/kg

Specific Stiffness (E / density)

9.7 MN·m/kg
6.7 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-3XXXP
Default condition——
Relative cost$$$ Premium$$ Standard
Min. machined wall——
Best machined surface——

G-3 vs XXXP — frequently asked

Is G-3 stronger than XXXP?

Yes. G-3 has a typical tensile strength of 250 MPa (36.3 ksi) against 105 MPa (15.2 ksi) for XXXP — about 138% more.

Which is cheaper, G-3 or XXXP?

XXXP 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 XXXP?

XXXP. Its machinability rates excellent (85/100) against fair (42/100) for G-3.

Ready to make it?

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