PEKK FFF vs PEKK GF30
Polymer · PEKK grade comparison
PEKK FFF and PEKK GF30 are two grades of the same polymer grade, PEKK: FFF (FFF/FDM filament grade) versus GF30 (30 % glass-fiber reinforced). The chemistry is identical, so every difference below comes from the condition. PEKK GF30 is the stronger of the two: yield strength 95 MPa (13.8 ksi) against 90 MPa (13.1 ksi) for PEKK FFF, about 6% more; tensile strength follows at 160 MPa (23.2 ksi) vs 93 MPa (13.5 ksi). In exchange, PEKK FFF is the more ductile: elongation 4% versus 2.5% for PEKK GF30. PEKK FFF is lighter (1.3 g/cm³ vs 1.53 g/cm³ for PEKK GF30) and PEKK GF30 is stiffer (11 GPa vs 3.8 GPa). On the shop floor, PEKK FFF machines more easily (good vs fair) and PEKK GF30 welds better (good vs fair).
PEKK FFFChoose it when the part is bent, formed or impact-loaded, or when weight is the constraint.
PEKK GF30Choose it when strength drives the design, or when it will be welded.
PEKK FFF vs PEKK GF30: 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)
Yield Strength (0.2% offset)
Elongation at Break
Compressive Strength
Flexural Strength
Flexural Modulus
Shear Strength
Fracture Toughness (K_IC)
Izod Impact, Notched
Hardness, Rockwell M
Same in both: Shear Modulus 1.4 GPa0.2 Msi · Bulk Modulus 7 GPa0.94 Msi · Poisson's Ratio 0.4 · Compressive Modulus 3.5 GPa0.51 Msi · Hardness, Shore D 86 Shore D
Physical
Density and transition temperatures.
Density
Same in both: Melting Temperature (Tm) 332°C630 °F · Glass Transition (Tg) 162°C324 °F · Water Absorption (24 h) 0.15% · Water Absorption (Saturation) 0.5%
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Thermal Expansion (CTE, 20–100 °C)
Heat Deflection Temp. @ 0.45 MPa
Heat Deflection Temp. @ 1.8 MPa
Same in both: Specific Heat Capacity 1,050 J/kg·K0.25 BTU/lb·°F · Max Service Temperature (continuous) 240°C464 °F · Min Service Temperature -60°C-76 °F · Limiting Oxygen Index 40% · Max Service Temperature (short-term) 300°C572 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Resistivity 1×10¹⁴ Ω·m3.94×10²¹ µΩ·in · Dielectric Strength 22 kV/mm559 V/mil · Dielectric Constant (1 MHz) 3.3 · Dissipation Factor (1 MHz) 0.004 · Volume Resistivity 1×10¹⁶ Ω·cm · Surface Resistivity 1×10¹⁵ Ω · Comparative Tracking Index (CTI) 175 V
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: UV / Weathering Resistance 45 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Weldability
Formability (cold)
Mold Shrinkage
Processing Melt Temperature (typ.)
Same in both: Polishability 60 / 100 · Mold Temperature (typ.) 200°C392 °F
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 330 MJ/kg141,875 BTU/lb · Embodied Carbon (primary production) 18 kg CO₂/kg · Embodied Water 500 L/kg59.9 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.
PEKK FFF vs PEKK GF30 — frequently asked
Is PEKK GF30 stronger than PEKK FFF?
Yes. PEKK GF30 has a typical yield strength of 95 MPa (13.8 ksi) against 90 MPa (13.1 ksi) for PEKK FFF — about 6% more. Tensile strength is 160 MPa (23.2 ksi) vs 93 MPa (13.5 ksi).
Which grade does FabDigit quote by default, FFF or GF30?
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, PEKK FFF or PEKK GF30?
PEKK FFF. Its machinability rates good (65/100) against fair (45/100) for PEKK GF30; for welding the order is PEKK GF30 first (good, 55/100) then PEKK FFF (fair, 35/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in PEKK FFF and PEKK GF30 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.