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G-3 vs GPO-3

Composite · grade comparison

G-3 and GPO-3 are both composite grades. G-3 is the stronger of the two: tensile strength 250 MPa (36.3 ksi) against 70 MPa (10.2 ksi) for GPO-3, about 3.6 times as much. G-3 is the more ductile: elongation 1.5% versus 1.2% for GPO-3. G-3 is stiffer (18 GPa vs 9 GPa).

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

G-3 vs GPO-3: properties

G-3GPO-3

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
0.28

Tensile Strength (Ultimate)

250 MPa36.3 ksi
70 MPa10.2 ksi

Elongation at Break

1.5%
1.2%

Compressive Strength

310 MPa45 ksi
210 MPa30.5 ksi

Compressive Modulus

16 GPa2.3 Msi
10 GPa1.5 Msi

Flexural Strength

310 MPa45 ksi
125 MPa18.1 ksi

Flexural Modulus

18 GPa2.6 Msi
9.5 GPa1.4 Msi

Shear Strength

120 MPa17.4 ksi
70 MPa10.2 ksi

Izod Impact, Notched

480 J/m9 ft·lbf/in
380 J/m7.1 ft·lbf/in

Hardness, Rockwell M

110 HRM
105 HRM

Physical

Density and transition temperatures.

Glass Transition (Tg)

160°C320 °F
—

Water Absorption (24 h)

1.2%
0.35%

Water Absorption (Saturation)

2.5%
0.9%

Same in both: Density 1.85 g/cm³0.07 lb/in³

Thermal

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

Thermal Conductivity

0.3 W/m·K0.17 BTU/hr·ft·°F
0.32 W/m·K0.18 BTU/hr·ft·°F

Specific Heat Capacity

1,150 J/kg·K0.27 BTU/lb·°F
1,100 J/kg·K0.26 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

Limiting Oxygen Index

40%
42%

Same in both: Max Service Temperature (continuous) 130°C266 °F · Min Service Temperature -50°C-58 °F · Max Service Temperature (short-term) 180°C356 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

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

Dielectric Constant (1 MHz)

6
4.6

Dissipation Factor (1 MHz)

0.04
0.025

Volume Resistivity

1×10¹² Ω·cm
1×10¹³ Ω·cm

Surface Resistivity

1×10¹¹ Ω
1×10¹³ Ω

Comparative Tracking Index (CTI)

125 V
600 V

Same in both: Dielectric Strength 14 kV/mm356 V/mil

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

72 / 100
75 / 100

UV / Weathering Resistance

30 / 100
55 / 100

Manufacturability

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

Machinability

42 / 100
45 / 100

Polishability

25 / 100
20 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

78 MJ/kg33,534 BTU/lb
70 MJ/kg30,095 BTU/lb

Embodied Carbon (primary production)

4.5 kg CO₂/kg
4.2 kg CO₂/kg

Embodied Water

190 L/kg22.8 gal/lb
120 L/kg14.4 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
38 kN·m/kg

Specific Stiffness (E / density)

9.7 MN·m/kg
4.9 MN·m/kg

Thermal Diffusivity

0.1 mm²/s
0.2 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

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

G-3 vs GPO-3 — frequently asked

Is G-3 stronger than GPO-3?

Yes. G-3 has a typical tensile strength of 250 MPa (36.3 ksi) against 70 MPa (10.2 ksi) for GPO-3 — about 3.6 times as much.

Which is cheaper, G-3 or GPO-3?

Both sit in the same relative cost tier ($$$, premium); the part price will be decided by machining time, tolerance and quantity rather than by the material.

When should I choose G-3 over GPO-3?

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

Ready to make it?

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