PEKK · reinforced grade
PEKK-CF
Properties of the CF condition, compared with the other PEKK grades.
Use where maximum stiffness, dimensional stability and low CTE are needed (aerospace brackets, tooling); sacrifices ductility and abrades tooling.
What is PEKK-CF?
PEKK-CF is PEKK in the CF grade — use where maximum stiffness, dimensional stability and low CTE are needed (aerospace brackets, tooling); sacrifices ductility and abrades tooling. PEKK-CF has a yield strength of 95 MPa (13.8 ksi) and a tensile strength of 145 MPa (21 ksi) — stronger than 93% of polymer grades. Elongation at break is 2% and the elastic modulus is 14 GPa (2.03 Msi). PEKK-CF has a density of 1.42 g/cm³ (0.0513 lb/in³), heavier than 82% of polymer grades. Its glass-transition temperature is 162°C (324 °F). Unfilled is the default condition FabDigit quotes; CF is available on request or by drawing note.
Advantages
- Conducts heat well — 0.7 W/m·K (0.404 BTU/hr·ft·°F), better than 99% of polymer grades
- Stiff — 14 GPa (2.03 Msi), better than 98% of polymer grades
- High service temperature — 260°C (500 °F), better than 97% of polymer grades
- High strength — 95 MPa (13.8 ksi), better than 93% of polymer grades
- Good corrosion resistance — 92/100, better than 91% of polymer grades
Limitations
- High embodied carbon — 18 kg CO₂/kg, worse than 99% of polymer grades
- Limited ductility — 2%, worse than 94% of polymer grades
- Heavy — 1.42 g/cm³ (0.0513 lb/in³), worse than 82% of polymer grades
- Difficult to machine — 40/100, worse than 81% of polymer grades
PEKK-CF properties
Typical room-temperature values for PEKK-CF — 13 properties are specific to this condition; the rest are grade-level values shared by every PEKK grade. Each bar shows where the value sits among the polymer grades in FabDigit's library — further right is higher.
Physical5
PEKK-CF has a density of 1.42 g/cm³ (0.0513 lb/in³), heavier than 82% of polymer grades. Its glass-transition temperature is 162°C (324 °F).
Mechanical16
PEKK-CF has a yield strength of 95 MPa (13.8 ksi) and a tensile strength of 145 MPa (21 ksi) — stronger than 93% of polymer grades. Elongation at break is 2% and the elastic modulus is 14 GPa (2.03 Msi).
Thermal10
PEKK-CF is rated for continuous service to 260°C (500 °F). It conducts heat at 0.7 W/m·K (0.404 BTU/hr·ft·°F), better than 99% of polymer grades. Thermal expansion is 16 µm/m·K (8.89 µin/in·°F).
Electrical7
PEKK-CF is an electrical insulator with a dielectric strength of 22 kV/mm (558.8 V/mil) and a resistivity of 100 Ω·m.
Chemical & Environmental3
Corrosion resistance is excellent (92/100), better than 91% of polymer grades. UV resistance is fair.
Sustainability4
Producing a kilogram of PEKK-CF takes about 330 MJ of energy and emits 18 kg of CO₂ — more than 99% of polymer grades. Typical recycled content is 0%.
Manufacturability7
PEKK-CF's machinability is fair (40/100, worse than 81% of polymer grades); weldability good (55/100); formability fair (35/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other PEKK grades and fills
PEKK is also supplied in 9 other conditions. The full side-by-side table is on the PEKK overview.
- UnfilledDefaultDefault choice for ductile, low-outgassing, flame-retardant parts where isotropy and toughness matter more than stiffness.95 MPa tensile
- GF30Pick for stiff, creep-resistant, electrically insulating parts at elevated temperature at lower cost than carbon fiber.160 MPa tensile
- CFUse where maximum stiffness, dimensional stability and low CTE are needed (aerospace brackets, tooling); sacrifices ductility and abrades tooling.145 MPa tensile
- FFFPick when quoting as-printed extruded parts; expect strong anisotropy with Z-direction roughly 60–70 % of in-plane strength.93 MPa tensile
- ESDUse for satellite, fuel-system and electronics-handling parts requiring controlled surface resistivity without sacrificing PEKK's heat and FST behaviour.87 MPa tensile
Working with PEKK-CF
Is PEKK easy to machine?
Machines like PEEK with sharp carbide/PCD tools, high speed, light feeds and air or flood cooling; stress-relieve (annealing near 200 °C) before finish cuts to avoid distortion.
Can PEKK be welded?
Joinable by laser, ultrasonic, IR and hot-plate welding as well as PAEK-compatible epoxy adhesives after plasma or abrasive surface activation; no solvent bonding.
Can PEKK be formed, bent or molded?
Requires 340–420 °C melt, 160–230 °C tools and dry feedstock (<0.02 % moisture, 150 °C for 3–4 h); FFF needs a 400 °C-class hot end plus 130–200 °C chamber and post-print anneal for crystallinity and Z-strength.
What surface finishes work on PEKK?
Sand/bead-blast or vapour-smooth-free finishing only; no anodizing — parts can be painted or metallised after plasma treatment, and machined surfaces polish to a semi-gloss tan finish.
PEKK chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| carbon fiberCF variants only | 0 – 30 | 0 |
| glass fiberGF variants only | 0 – 40 | 0 |
| carbon nanotubeESD variant only | 0 – 5 | 0 |
| polyetherketoneketone repeat unit (from T/I isomer ratio ~60:40 to 80:20 sets Tm; unfilled default | balance | — |
PEKK-CF — frequently asked
What is PEKK-CF used for?
PEKK-CF is typically used for aerospace brackets, air and fluid ducting, satellite components, aerospace composite tooling and structures, electrical insulation parts and implantable orthopaedic devices. In short: space-grade performance.
What is the yield strength of PEKK-CF?
PEKK-CF has a typical yield strength of 95 MPa (13.8 ksi) and a tensile strength of 145 MPa (21 ksi) — stronger than 93% of polymer grades. Strength varies by condition: see the 10 listed tempers.
Is PEKK-CF easy to machine?
Not especially — machinability is rated fair (40/100, worse than 81% of polymer grades). Machines like PEEK with sharp carbide/PCD tools, high speed, light feeds and air or flood cooling; stress-relieve (annealing near 200 °C) before finish cuts to avoid distortion.
Can PEKK-CF be welded?
Yes — weldability is rated good (55/100). Joinable by laser, ultrasonic, IR and hot-plate welding as well as PAEK-compatible epoxy adhesives after plasma or abrasive surface activation; no solvent bonding.
What surface finishes work on PEKK-CF?
Sand/bead-blast or vapour-smooth-free finishing only; no anodizing — parts can be painted or metallised after plasma treatment, and machined surfaces polish to a semi-gloss tan finish.
Can PEKK-CF be formed, bent or molded?
Requires 340–420 °C melt, 160–230 °C tools and dry feedstock (<0.02 % moisture, 150 °C for 3–4 h); FFF needs a 400 °C-class hot end plus 130–200 °C chamber and post-print anneal for crystallinity and Z-strength.
What is the maximum service temperature of PEKK-CF?
PEKK-CF is rated for continuous use to about 260°C (500 °F), and briefly to 300°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in PEKK-CF?
Yes — PEKK-CF is available for 3D printing with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- Kepstan PEKK 6000/7000/8000 series technical data and processing guide — Arkema (2022)
- Antero 800NA and Antero 840CN03 PEKK FDM material datasheets — Stratasys (2023)
- Engineering Plastics — polyaryletherketone property overview — ASM International (2000)
- CAMPUS / UL Prospector PAEK property listings — CWFG / UL Solutions (2024)
- ISO 10993 series (biological evaluation of medical devices) — ISO (2018)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.