FR-2 vs XXP
Composite · grade comparison
FR-2 and XXP are both composite grades. FR-2 is the stronger of the two: tensile strength 92 MPa (13.3 ksi) against 83 MPa (12 ksi) for XXP, about 11% more. XXP is lighter (1.35 g/cm³ vs 1.55 g/cm³ for FR-2) and XXP is stiffer (8 GPa vs 7.5 GPa).
FR-2Choose it when strength drives the design.
XXPChoose it when weight is the constraint, or when the part sees heat.
FR-2 vs XXP: 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
Tensile Strength (Ultimate)
Elongation at Break
Compressive Strength
Flexural Strength
Flexural Modulus
Fracture Toughness (K_IC)
Izod Impact, Notched
Compressive Modulus
Same in both: Poisson's Ratio 0.25 · Shear Strength 90 MPa13.1 ksi · Hardness, Rockwell M 105 HRM
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
Thermal Expansion (CTE, 20–100 °C)
Max Service Temperature (continuous)
Heat Deflection Temp. @ 1.8 MPa
Limiting Oxygen Index
Max Service Temperature (short-term)
Same in both: Specific Heat Capacity 1,300 J/kg·K0.31 BTU/lb·°F · Min Service Temperature -40°C-40 °F
Electrical
Conductivity and insulation.
Dielectric Constant (1 MHz)
Comparative Tracking Index (CTI)
Same in both: Electrical Resistivity 1×10⁹ Ω·m3.94×10¹⁶ µΩ·in · Dielectric Strength 20 kV/mm508 V/mil · Dissipation Factor (1 MHz) 0.04 · Volume Resistivity 1×10¹¹ Ω·cm · Surface Resistivity 1×10¹¹ Ω
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.
Same in both: Machinability 75 / 100 · Polishability 25 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Typical Recycled Content
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Thermal Diffusivity
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.
Manufacturing and finishing
| Capability | FR-2 | XXP |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$ Standard | $$ Standard |
| Min. machined wall | — | — |
| Best machined surface | — | — |
FR-2 vs XXP — frequently asked
Is FR-2 stronger than XXP?
Yes. FR-2 has a typical tensile strength of 92 MPa (13.3 ksi) against 83 MPa (12 ksi) for XXP — about 11% more.
Which is cheaper, FR-2 or XXP?
Both sit in the same relative cost tier ($$, standard); the part price will be decided by machining time, tolerance and quantity rather than by the material.
When should I choose FR-2 over XXP?
Pick FR-2 when strength drives the design. Pick XXP when weight is the constraint, or when the part sees heat.
Ready to make it?
Upload a CAD file and FabDigit prices the part in FR-2 and XXP 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.