PA6/66 CF20 vs PA6/66 GF15
Polymer · PA6/66 grade comparison
PA6/66 CF20 and PA6/66 GF15 are two grades of the same polymer grade, PA6/66: CF20 (20% carbon fiber reinforced) versus GF15 (15% short glass fiber reinforced). The chemistry is identical, so every difference below comes from the condition. PA6/66 CF20 is the stronger of the two: tensile strength 190 MPa (27.6 ksi) against 115 MPa (16.7 ksi) for PA6/66 GF15, about 65% more. In exchange, PA6/66 GF15 is the more ductile: elongation 5% versus 2.5% for PA6/66 CF20. PA6/66 CF20 is stiffer (15 GPa vs 5.5 GPa) and PA6/66 GF15 runs hotter in service (105°C vs 90°C continuous). On the shop floor, PA6/66 GF15 machines more easily (52 vs 38 out of 100).
PA6/66 CF20Choose it when strength drives the design.
PA6/66 GF15Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.
PA6/66 CF20 vs PA6/66 GF15: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all polymer 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 polymer 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
Flexural Strength
Flexural Modulus
Same in both: Shear Modulus 1 GPa0.15 Msi · Poisson's Ratio 0.39 · Yield Strength (0.2% offset) 72 MPa10.4 ksi · Compressive Strength 80 MPa11.6 ksi · Shear Strength 55 MPa8 ksi · Izod Impact, Notched 75 J/m1.4 ft·lbf/in · Hardness, Shore D 80 Shore D · Hardness, Rockwell M 78 HRM · Hardness, Rockwell R 118 HRR
Physical
Density and transition temperatures.
Density
Same in both: Melting Temperature (Tm) 196°C385 °F · Glass Transition (Tg) 50°C122 °F · Water Absorption (24 h) 1.8% · Water Absorption (Saturation) 9.5%
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. @ 0.45 MPa
Heat Deflection Temp. @ 1.8 MPa
Same in both: Specific Heat Capacity 1,700 J/kg·K0.41 BTU/lb·°F · Min Service Temperature -40°C-40 °F · Vicat Softening Point (B50) 180°C356 °F · Limiting Oxygen Index 24% · Max Service Temperature (short-term) 150°C302 °F
Electrical
Conductivity and insulation.
Surface Resistivity
Same in both: Electrical Resistivity 1×10¹² Ω·m3.94×10¹⁹ µΩ·in · Dielectric Strength 25 kV/mm635 V/mil · Dielectric Constant (1 MHz) 3.4 · Dissipation Factor (1 MHz) 0.03 · Volume Resistivity 1×10¹⁴ Ω·cm · Comparative Tracking Index (CTI) 600 V
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Corrosion Resistance 60 / 100 · UV / Weathering Resistance 30 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Mold Shrinkage
Same in both: Weldability 78 / 100 · Formability (cold) 60 / 100 · Polishability 55 / 100 · Melt Flow Rate 25 g/10 min · Processing Melt Temperature (typ.) 260°C500 °F · Mold Temperature (typ.) 70°C158 °F
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 122 MJ/kg52,451 BTU/lb · Embodied Carbon (primary production) 7.5 kg CO₂/kg · Embodied Water 450 L/kg53.9 gal/lb · Typical Recycled Content 0%
Strength versus weight
Yield strength against density for every polymer grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
PA6/66 CF20 vs PA6/66 GF15 — frequently asked
Is PA6/66 CF20 stronger than PA6/66 GF15?
Yes. PA6/66 CF20 has a typical tensile strength of 190 MPa (27.6 ksi) against 115 MPa (16.7 ksi) for PA6/66 GF15 — about 65% more.
Which grade does FabDigit quote by default, CF20 or GF15?
Specify the condition in the material field or the drawing note; FabDigit prices the quote for the state you call out.
Which is easier to machine, PA6/66 CF20 or PA6/66 GF15?
PA6/66 GF15, by a small margin. Both rate fair for machinability — 52/100 against 38/100 for PA6/66 CF20.
Ready to make it?
Upload a CAD file and FabDigit prices the part in PA6/66 CF20 and PA6/66 GF15 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.