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FR-2 vs GPO-3

Composite · grade comparison

FR-2 and GPO-3 are both composite grades. FR-2 is the stronger of the two: tensile strength 92 MPa (13.3 ksi) against 70 MPa (10.2 ksi) for GPO-3, about 31% more. FR-2 is lighter (1.55 g/cm³ vs 1.85 g/cm³ for GPO-3) and GPO-3 is stiffer (9 GPa vs 7.5 GPa). On the shop floor, FR-2 machines more easily (very good vs fair) and FR-2 sits in a lower cost tier (standard, $$) than GPO-3 (premium, $$$).

FR-2Choose it when strength drives the design, or when weight is the constraint.

GPO-3Choose it when the part sees heat.

FR-2 vs GPO-3: properties

FR-2GPO-3

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

7.5 GPa1.1 Msi
9 GPa1.3 Msi

Poisson's Ratio

0.25
0.28

Tensile Strength (Ultimate)

92 MPa13.3 ksi
70 MPa10.2 ksi

Elongation at Break

1.1%
1.2%

Compressive Strength

250 MPa36.3 ksi
210 MPa30.5 ksi

Flexural Strength

115 MPa16.7 ksi
125 MPa18.1 ksi

Flexural Modulus

7.8 GPa1.1 Msi
9.5 GPa1.4 Msi

Shear Strength

90 MPa13.1 ksi
70 MPa10.2 ksi

Fracture Toughness (K_IC)

1.7 MPa·√m1.5 ksi·√in
—

Izod Impact, Notched

31 J/m0.58 ft·lbf/in
380 J/m7.1 ft·lbf/in

Compressive Modulus

—
10 GPa1.5 Msi

Same in both: Hardness, Rockwell M 105 HRM

Physical

Density and transition temperatures.

Density

1.55 g/cm³0.06 lb/in³
1.85 g/cm³0.07 lb/in³

Glass Transition (Tg)

110°C230 °F
—

Water Absorption (24 h)

0.55%
0.35%

Water Absorption (Saturation)

2%
0.9%

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

Specific Heat Capacity

1,300 J/kg·K0.31 BTU/lb·°F
1,100 J/kg·K0.26 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

20 µm/m·K11.1 µin/in·°F
22 µm/m·K12.2 µin/in·°F

Max Service Temperature (continuous)

105°C221 °F
130°C266 °F

Min Service Temperature

-40°C-40 °F
-50°C-58 °F

Heat Deflection Temp. @ 1.8 MPa

130°C266 °F
—

Limiting Oxygen Index

30%
42%

Max Service Temperature (short-term)

260°C500 °F
180°C356 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

1×10⁹ Ω·m3.94×10¹⁶ µΩ·in
1×10¹¹ Ω·m3.94×10¹⁸ µΩ·in

Dielectric Strength

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

Dissipation Factor (1 MHz)

0.04
0.025

Volume Resistivity

1×10¹¹ 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 Constant (1 MHz) 4.6

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

48 / 100
75 / 100

UV / Weathering Resistance

25 / 100
55 / 100

Manufacturability

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

Machinability

75 / 100
45 / 100

Polishability

25 / 100
20 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

85 MJ/kg36,543 BTU/lb
70 MJ/kg30,095 BTU/lb

Embodied Carbon (primary production)

4.5 kg CO₂/kg
4.2 kg CO₂/kg

Embodied Water

250 L/kg30 gal/lb
120 L/kg14.4 gal/lb

Typical Recycled Content

5%
0%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

59 kN·m/kg
38 kN·m/kg

Specific Stiffness (E / density)

4.8 MN·m/kg
4.9 MN·m/kg

Same in both: Thermal Diffusivity 0.2 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

CapabilityFR-2GPO-3
Default condition——
Relative cost$$ Standard$$$ Premium
Min. machined wall——
Best machined surface——

FR-2 vs GPO-3 — frequently asked

Is FR-2 stronger than GPO-3?

Yes. FR-2 has a typical tensile strength of 92 MPa (13.3 ksi) against 70 MPa (10.2 ksi) for GPO-3 — about 31% more.

Which is cheaper, FR-2 or GPO-3?

FR-2 is the lower-cost material: it sits in the standard tier ($$) while GPO-3 is premium ($$$). 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, FR-2 or GPO-3?

FR-2. Its machinability rates very good (75/100) against fair (45/100) for GPO-3.

Ready to make it?

Upload a CAD file and FabDigit prices the part in FR-2 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.