3D Printing Info

Filament comparison

PCTG vs PEEK-CF

Compare printing settings, strength, heat resistance, dated prices and sources.

PCTG guideFibre-reinforced PEEK guide

2 selected · all documented properties

Open these two in the interactive comparisonMore PCTG comparisonsMore PEEK-CF comparisons
PCTG vs PEEK-CF — documented properties and sources
PropertyPCTGPETGFibre-reinforced PEEKHIGHTEMP
Market snapshot
Listing priceUSD/kg; dated snapshots$34.99/kg median; $14.00–$50.67/kg across 5 dated product listings$597.50/kg median; $448.00–$695.00/kg across 5 dated product listings
Identity & Market
Base polymer / chemistryPoly(cyclohexylenedimethylene terephthalate) glycol — a copolyester with a higher cyclohexanedimethanol content than PETG[1][2]Short-fibre reinforced PEEK. 3DXTech's CarbonX grade is nominally 10 wt% carbon and its FibreX grade 20 wt% glass; LEHVOSS Luvocom 3F PEEK CF 9676 is 15 wt% carbon; Ensinger's machining stock runs to 30 wt% carbon[3][4][5][6]
Densityg/cm³1.23 (Extrudr, ASTM D792; 3DXTech, ISO 1183)[2][7]1.39 (ISO 1183)[3]
Typical priceUSD/kg1 kg spools cluster near 34[8][7][9]1 kg-equivalent spools span 448–972; the middle of the market is about 598[4][5][10]
Price range across brandsUSD/kg14–51 across brands; CHCKX 14 in a 10-roll bundle, Push Plastic 30, Proto-pasta 35 at 1 kg, 3DXTech 51[8][7][11]448-972 across formats and filler types; IEMAI 3D CF-PEEK and GF-PEEK 448 at 1 kg, 3DXTech CarbonX PEEK+CF10 598 at 2 kg and FibreX PEEK+GF20 695 at 1 kg, Luvocom 3F PEEK CF 9676 648 at 2 kg[4][5][10][12]
Market availability1–5Available from several mainstream brands[8][7][9][13]Niche, a handful of specialist brands[4][5]
Spool sizes & diameters1.75 and 2.85 mm; 0.5, 0.75, 1, 3 and 5 kg spools[8][9][7]1.75 and 2.85 mm; 200 g to 2 kg spools[4][5]
Typical applicationsTransparent covers, guards and impact-loaded parts where PETG cracks[1][2]Stiff aerospace and oil-and-gas parts where PEEK alone is not rigid enough[3]
Printing Parameters
Nozzle temperature°C250–270 (Spectrum, Extrudr)[1][2]Not documented
Bed temperature°C60–100 (Spectrum)[1]Not documented
Enclosure / chamber requirement1–5Open frame is fine — Spectrum and Extrudr both say a closed chamber is not necessary, Extrudr adds it helps on larger parts[1][2]Actively heated chamber required[14][15]
Part cooling fanUp to 100 % (Spectrum); 20–50 % (Extrudr)[1][2]Not documented
Bed surface & adhesion aidTextured PEI, satin or powder-coated sheets; on smooth PEI a glue stick acts as a release agent[16][17]Not documented
Maximum volumetric flow (mm³/s; see test conditions)mm³/s1.6–16 at the 20–200 mm/s Extrudr rates the material for, on a 0.4 mm nozzle at 0.2 mm layer[2][18]Not documented
Warping tendency1–5Not documentedModerate — needs adhesion aid or draught shield; the fibre cuts PEEK's crystallisation shrinkage[3]
Bed-adhesion difficulty1–5Needs the right surface or a thin adhesive — the problem is releasing the part, not sticking it[16][17]Not documented
Stringing / oozing tendency1–5Moderate — retraction tuning needed; Polymaker names stringing as PETG's common quirk[17]Not documented
Shrinkage%0.2–0.5 (Extrudr, ASTM D955)[2]Not documented
Overall printing difficulty1–5Easy — minor profile tuning[1][2]Expert / industrial hardware only[14][15]
Hardware Wear & Reliability
Nozzle hardness required1–4Brass fine indefinitely — Extrudr explicitly states no hardened nozzle is needed[2]Hardened steel required[3]
Abrasiveness1–5Non-abrasive[2]Highly abrasive — standard CF composite[3]
Nozzle clog risk1–5Low — 3DXTech lists no special nozzle concerns and no minimum layer height for PCTG, only a 65 °C pre-dry[19]High — jams from moisture, heat creep or particles; 3DXTech adds a hardened 0.4 mm minimum nozzle and 0.25 mm layers to the mandatory 120 °C pre-dry[20][21]
Heat-creep / jam sensitivity1–5Slightly sensitive[22]Not documented
Hotend requirementNo special hot-end required[22]Not documented
Moisture Behaviour
Moisture absorption (hygroscopicity)1–5Moderate (0.3–0.8 %) — the copolyester matrix reaches 0.40 % saturated at 25 °C / 55 % RH and 3DXTech specifies a 65 °C, 4 h pre-dry[16][19]Not documented
Equilibrium moisture content at ~50 % RH%Not documented0.06 in 24 h on extruded CF30 stock (ASTM D570)[6]
Symptoms when wetBubbling and popping at the nozzle, stringing and a rough surface[23]Not documented
Effect of moisture on strengthPolymaker groups PETG with nylon, PVA and TPU as highly hygroscopic; no dry-versus-conditioned strength figures are published for this grade and the loss shows as bubbling and poor layer adhesion[23]No dry-versus-conditioned figures are published; 3DXTech mandates a 120 °C, 4 h pre-dry before every print because trapped water flashes to steam at these nozzle temperatures[20]
Storage requirementSealed with desiccant; Polymaker groups PETG with the highly hygroscopic materials[23][17]Not documented
Mechanical Properties
Tensile strength (XY)MPa43–44 at yield and 45–46 at break (ISO 527, injection-moulded resin data from Spectrum and Extrudr); 48 on My Tech Fun printed bars[1][2][24]105 at break (printed XY, ISO 527, CF10); 121 at yield on extruded CF30 stock (ASTM D638)[3][6]
Young's modulusMPaNot documented8100 (printed XY, ISO 527, CF10) — more than double unfilled PEEK; 6343 on extruded CF30 stock (ASTM D638)[3][6]
Elongation at break%215–220 at break on moulded specimens (ISO 527); 4.3–4.4 at yield[1][2]3 at break (printed XY, ISO 527), against 28 for unfilled PEEK[3][25]
Flexural strengthMPaNot documented136 (printed XY, ISO 178, CF10); 193 on extruded CF30 stock (ASTM D790)[3][6]
Flexural modulusMPaNot documented8300 (printed XY, ISO 178, CF10); 7171 on extruded CF30 stock (ASTM D790)[3][6]
Charpy impact, notchedkJ/m²93–94 notched Izod at 23 °C on moulded specimens (ISO 180); 3DXTech quotes 8 by ISO 180/A[1][2][7]Not documented
Other impact dataIzod 4.14 kJ/m² on My Tech Fun printed bars, against 3.37 for PETG on the same rig[24]Izod notched 61.9 J/m on extruded CF30 stock, converted from 1.16 ft-lb/in (ASTM D256)[6]
Layer adhesion / Z tensileMPa21.6 on My Tech Fun 4×4 mm printed bars, against 32.9 for PETG[24]Not documented
Brittleness1–5Tough — absorbs impact, yields before breaking[1][2]Brittle — snaps with little warning; elongation falls from 28 % to 3 %[3][25]
Hardness (scale-specific)Shore A / Shore D / Rockwell69 Shore D measured by My Tech Fun, against 72 for PETG[24]Rockwell M107 on extruded PEEK-CF30 stock (ASTM D785), against M100 unfilled[6][26]
Creep resistance / sustained load1–5Below average — a 12 mm bar sagged to 19.4 mm over 5 days at 1.25 kg, slightly worse than PETG's 18.2[24]Excellent — holds load for years. Ensinger rates carbon-fibre PEEK stock as very highly creep resistant and specifies 260 °C continuous service[6]
Fatigue / repeated-flex resistance1–5Good — 215 % elongation at break and 94 kJ/m² notched Izod on moulded specimens (Extrudr, Spectrum)[1][2]Good. Victrex rates PEEK for long-term fatigue as well as creep; the fibre cuts elongation at break from 28 % to 3 %, which limits repeated large-strain flexing[27][3][25]
Elasticity / flexibility1–5Slightly flexible in thin sections[24]Rigid[3]
Thermal Properties
HDT at 0.45 MPa°CNot documented265 (printed XY, ISO 75 at 0.45 MPa, CarbonX PEEK+CF10) against 140 for unfilled PEEK[3][25]
HDT at 1.8 MPa°CNot documented316 on extruded CF30 stock, converted from 600 °F at 264 psi (ASTM D648)[6]
Glass transition (Tg)°C78 (3DXTech, DSC)[7]143 (DSC, CarbonX PEEK+CF10) — the fibre does not move the glass transition[3]
Melting point / Vicat°CAmorphous — no melting point; Vicat 88 (Spectrum, Extrudr)[1][2]334 melting on extruded CF30 stock, converted from 633 °F[6]
Continuous service temperature°C68 — loaded bars begin to move at this temperature, against 65 for PETG[24]260 long-term on extruded CF30 stock, converted from 500 °F; 300 short term[6]
Thermal expansion (CTE)µm/m·KNot documented14.4 (extruded PEEK-CF30 stock, ASTM D696; source states 0.80e-5 in/in/°F) — about a third of unfilled PEEK[6][26]
Flammability / UL 94Flammable; no UL 94 rating published for standard grades[28]UL 94 V-0 on the base resin; Ensinger lists extruded PEEK-CF30 stock as inherently flame resistant[25][6]
Environment & Chemical
Chemical resistanceWithstands acids, alkalis, oils and UV exposure[17]Not documented
Water / humidity resistance in service1–5Good — minor absorption; Spectrum describes the polymer as hydrophobic[1]Not documented
Food contactNot certified for food contact as filament[17]Not documented
Biodegradability / compostabilityNot biodegradable[17]Not documented
RecyclabilityNot accepted in household plastic collection[17]Not documented
Electrical & ESD propertiesSurface resistance above 10¹³ ohm/sq — insulating (3DXTech, ASTM D257)[7]Surface resistance above 10⁹ ohm/sq — not static-dissipative (ASTM D257)[3]
Health & Safety
Fume toxicity1–5Moderate — measurable VOCs and UFPs, ventilation advised[29]Moderate — measurable VOCs and UFPs, ventilation advised. None of these polymers was in the chamber study, and all are processed far above the temperatures it covered[29]
Ventilation / filtration requirement1–5Open a window / occasional ventilation[29]Ventilated room or enclosure recommended[29]
Dust & fibre handling hazardNot documentedCarbon fibre is bound in the matrix; sanding dust should not be inhaled[3]
Post-Processing
Sanding & machiningSands poorly — the material is tough and gums rather than powders[22]Not documented
Gluing & solvent weldingCyanoacrylate; no common solvent welds PETG cleanly[22]Not documented
Vapour / chemical smoothingNo practical vapour smoothing[22]Not documented
Support material pairingPrints its own supports; Polymaker rates PolyDissolve S1 for PETG[22]Not documented
Dimensional accuracy & detailOptical clarity is the selling point; Extrudr recommends a layer height at most 50 % of nozzle diameter[2]Not documented
Solvents & Solubility
Soluble inNo common workshop solvent; Eastman's CHDM copolyester data shows 1,2-dichloroethane destroying it within a week.[30]95–98 wt% sulphuric acid dissolves the matrix at 40–70 °C and leaves the fibre. Nothing else touches PEEK.[31][32]
Softened or crazed byAcetone, ethyl acetate, toluene and DMF swell and soften the copolyester; methanol crazes it (Eastman, 1 y at 23 °C).[30]Concentrated nitric, hydrofluoric, hydrobromic and hydriodic acids attack it; DCM, DMSO and THF swell thin-walled sections.[33][32]
Solvent welding & smoothing agentDichloromethane brushed on is the only agent that smooths PETG — a controlled carcinogen, not workshop stock.[34]None — no solvent softens PEEK, so parts are joined thermally or mechanically, never chemically.[33][32]

Material entries describe families or representative grades, not an interchangeable specification for every spool. Test methods, orientations and conditions may differ. Unknown values are marked “Not documented”. Prices and source dates remain historical snapshots; check the linked guide for product details. Differences highlight text, not a universal winner.

Sources for this comparison

  1. Spectrum Premium PCTG Technical Data Sheet Spectrum Filaments · 2026-08 · tds
  2. Extrudr PCTG technical data Extrudr · 2026-08 · tds
  3. CarbonX Carbon Fiber PEEK Technical Data Sheet v3 3DXTech · 2026-08 · tds
  4. 3DXTech product catalogue 3DXTech · 2026-08 · vendor
  5. 3D4Makers product catalogue 3D4Makers · 2026-08 · vendor
  6. TECAPEEK CF30 black (PEEK-CF30) — stock shape properties Ensinger · 2026-08 · tds
  7. MAX-G PCTG Technical Data Sheet 3DXTech · 2026-08 · tds
  8. Push Plastic product catalogue Push Plastic · 2026-08 · vendor
  9. Proto-pasta product catalogue Proto-pasta · 2026-08 · vendor
  10. IEMAI 3D CF-PEEK 3D Printing Filament — store page IEMAI 3D · 2026-08 · vendor
  11. CHCKX 10KG Multicolor PCTG Filament bundle CHCKX (Amazon US) · 2026-08 · vendor
  12. IEMAI 3D GF-PEEK 3D Printing Filament — store page IEMAI 3D · 2026-08 · vendor
  13. Atomic Filament product catalogue Atomic Filament · 2026-08 · vendor
  14. Prusament PEI 1010 Technical Datasheet v1.0 Prusa Polymers · 2024-09 · tds
  15. Prusament PEI 1010 — material page Prusa Polymers · 2026-08 · doc
  16. Prusament PETG Technical Datasheet v1.1 Prusa Polymers · 2022-02 · tds
  17. PETG — material basics Polymaker Wiki · 2026-08 · doc
  18. Max volumetric speed Prusa Knowledge Base · 2026-08 · doc
  19. MAX-G PCTG — product page (print recommendations) 3DXTech · 2026-08 · doc
  20. CARBONX PEEK+CF10 — product page (print recommendations) 3DXTech · 2026-08 · doc
  21. Composite materials filled with carbon, kevlar or glass Prusa Knowledge Base · 2026-08 · doc
  22. PET and PETG — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  23. Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
  24. PCTG vs PETG comparison — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
  25. ThermaX PEEK Technical Data Sheet v3 3DXTech · 2026-08 · tds
  26. TECAPEEK natural (PEEK) — stock shape properties Ensinger · 2026-08 · tds
  27. PEEK polymers — product overview Victrex · 2026-08 · doc
  28. Prusament PETG V0 Technical Datasheet Prusa Polymers · 2026-08 · tds
  29. Emissions of Ultrafine Particles and Volatile Organic Compounds from Commercially Available Desktop Three-Dimensional Printers with Multiple Filaments (Azimi et al.) Environmental Science & Technology 50(3) 1260-1268 · 2016-01 · paper
  30. Eastman Spectar copolyester — Chemical resistance (unstressed bars, 1 year at 23 °C) Eastman Chemical Company · 2026-08 · tds
  31. The Effects of Sulfonated Poly(ether ether ketone) Ion Exchange Preparation Conditions on Membrane Properties Yee, Zhang & Ladewig, Membranes 3(3) 182–195 · 2013-07 · paper
  32. Chemical resistance — resistance of Ensinger plastics to chemicals (DIN 50 014, 23/50) Ensinger · 2026-08 · tds
  33. What solvents are not compatible with PEEK? — fluidics technical FAQ IDEX Health & Science · 2026-08 · doc
  34. Improve your 3D prints with chemical smoothing Prusa Research · 2026-08 · doc