FR-5 vs G-9
Composite · grade comparison
FR-5 and G-9 are both composite grades. FR-5 is the stronger of the two: tensile strength 340 MPa (49.3 ksi) against 240 MPa (34.8 ksi) for G-9, about 42% more. FR-5 is lighter (1.85 g/cm³ vs 1.95 g/cm³ for G-9) and FR-5 is stiffer (22 GPa vs 19 GPa). On the shop floor, FR-5 machines more easily (fair vs poor) and FR-5 sits in a lower cost tier (premium, $$$) than G-9 (high, $$$$).
FR-5Choose it when strength drives the design, or when weight is the constraint.
FR-5 vs G-9: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all composite grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all composite grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Elastic (Young's) Modulus
Shear Modulus
Tensile Strength (Ultimate)
Compressive Strength
Compressive Modulus
Flexural Strength
Flexural Modulus
Shear Strength
Izod Impact, Notched
Hardness, Rockwell M
Same in both: Poisson's Ratio 0.16
Physical
Density and transition temperatures.
Density
Glass Transition (Tg)
Water Absorption (24 h)
Water Absorption (Saturation)
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Limiting Oxygen Index
Same in both: Specific Heat Capacity 1,100 J/kg·K0.26 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 14 µm/m·K7.8 µin/in·°F · Max Service Temperature (continuous) 155°C311 °F · Min Service Temperature -60°C-76 °F · Max Service Temperature (short-term) 200°C392 °F
Electrical
Conductivity and insulation.
Electrical Resistivity
Dielectric Strength
Dielectric Constant (1 MHz)
Dissipation Factor (1 MHz)
Volume Resistivity
Surface Resistivity
Comparative Tracking Index (CTI)
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
UV / Weathering Resistance
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Polishability
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Same in both: Embodied Water 200 L/kg24 gal/lb · Typical Recycled Content 0%
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
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.
Manufacturing and finishing
| Capability | FR-5 | G-9 |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$$ Premium | $$$$ High |
| Min. machined wall | — | — |
| Best machined surface | — | — |
FR-5 vs G-9 — frequently asked
Is FR-5 stronger than G-9?
Yes. FR-5 has a typical tensile strength of 340 MPa (49.3 ksi) against 240 MPa (34.8 ksi) for G-9 — about 42% more.
Which is cheaper, FR-5 or G-9?
FR-5 is the lower-cost material: it sits in the premium tier ($$$) while G-9 is high ($$$$). 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-5 or G-9?
FR-5. Its machinability rates fair (45/100) against poor (30/100) for G-9.
Ready to make it?
Upload a CAD file and FabDigit prices the part in FR-5 and G-9 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.