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FR-5 vs GPO-1

Composite · grade comparison

FR-5 and GPO-1 are both composite grades. FR-5 is the stronger of the two: tensile strength 340 MPa (49.3 ksi) against 70 MPa (10.2 ksi) for GPO-1, about 4.9 times as much. FR-5 is stiffer (22 GPa vs 10 GPa).

FR-5Choose it when strength drives the design.

FR-5 vs GPO-1: properties

FR-5GPO-1

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

22 GPa3.2 Msi
10 GPa1.5 Msi

Shear Modulus

5.5 GPa0.8 Msi
—

Poisson's Ratio

0.16
0.25

Tensile Strength (Ultimate)

340 MPa49.3 ksi
70 MPa10.2 ksi

Compressive Strength

450 MPa65.3 ksi
190 MPa27.6 ksi

Compressive Modulus

20 GPa2.9 Msi
9 GPa1.3 Msi

Flexural Strength

480 MPa69.6 ksi
140 MPa20.3 ksi

Flexural Modulus

21 GPa3 Msi
9.5 GPa1.4 Msi

Shear Strength

140 MPa20.3 ksi
70 MPa10.2 ksi

Izod Impact, Notched

420 J/m7.9 ft·lbf/in
430 J/m8.1 ft·lbf/in

Hardness, Rockwell M

110 HRM
105 HRM

Physical

Density and transition temperatures.

Glass Transition (Tg)

170°C338 °F
120°C248 °F

Water Absorption (24 h)

0.15%
0.4%

Water Absorption (Saturation)

0.4%
1%

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

Thermal Expansion (CTE, 20–100 °C)

14 µm/m·K7.8 µin/in·°F
25 µm/m·K13.9 µin/in·°F

Min Service Temperature

-60°C-76 °F
-40°C-40 °F

Limiting Oxygen Index

32%
26%

Max Service Temperature (short-term)

200°C392 °F
180°C356 °F

Heat Deflection Temp. @ 1.8 MPa

—
200°C392 °F

Same in both: Specific Heat Capacity 1,100 J/kg·K0.26 BTU/lb·°F · Max Service Temperature (continuous) 155°C311 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

1×10¹² Ω·m3.94×10¹⁹ µΩ·in
1×10¹¹ Ω·m3.94×10¹⁸ µΩ·in

Dielectric Strength

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

Dielectric Constant (1 MHz)

4.8
5

Dissipation Factor (1 MHz)

0.022
0.025

Volume Resistivity

1×10¹⁴ Ω·cm
1×10¹³ Ω·cm

Same in both: Surface Resistivity 1×10¹³ Ω · Comparative Tracking Index (CTI) 200 V

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

80 / 100
78 / 100

Same in both: UV / Weathering Resistance 40 / 100

Manufacturability

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

Same in both: Machinability 45 / 100 · Polishability 25 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

110 MJ/kg47,292 BTU/lb
70 MJ/kg30,095 BTU/lb

Embodied Carbon (primary production)

6.5 kg CO₂/kg
4.2 kg CO₂/kg

Embodied Water

200 L/kg24 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)

184 kN·m/kg
38 kN·m/kg

Specific Stiffness (E / density)

11.9 MN·m/kg
5.4 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

CapabilityFR-5GPO-1
Default condition——
Relative cost$$$ Premium$$$ Premium
Min. machined wall——
Best machined surface——

FR-5 vs GPO-1 — frequently asked

Is FR-5 stronger than GPO-1?

Yes. FR-5 has a typical tensile strength of 340 MPa (49.3 ksi) against 70 MPa (10.2 ksi) for GPO-1 — about 4.9 times as much.

Which is cheaper, FR-5 or GPO-1?

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 FR-5 over GPO-1?

Pick FR-5 when strength drives the design.

Ready to make it?

Upload a CAD file and FabDigit prices the part in FR-5 and GPO-1 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.