3D Printing Info

Filament comparison

PEEK vs PETG-GF

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

PEEK guideGlass-fibre polyester (PETG-GF / PET-GF) guide

2 selected · all documented properties

Open these two in the interactive comparisonMore PEEK comparisonsMore PETG-GF comparisons
PEEK vs PETG-GF — documented properties and sources
PropertyPEEKHIGHTEMPGlass-fibre polyester (PETG-GF / PET-GF)PETG
Market snapshot
Listing priceUSD/kg; dated snapshots$531.87/kg median; $296.14–$770.00/kg across 5 dated product listings$27.38/kg median; $18.99–$29.99/kg across 3 dated product listings
Identity & Market
Base polymer / chemistryPolyether ether ketone — a semi-crystalline polyaryletherketone[1]Glass-fibre reinforced polyester. Polymaker's Fiberon PET-GF15 uses a PET rather than a PETG matrix and carries 15 wt% glass fibre[2]
Densityg/cm³1.30 (ISO 1183)[1][3]1.43 (Fiberon PET-GF15, ISO 1183)[2]
Typical priceUSD/kg1 kg-equivalent spools span 296–770; the middle of the market is about 532[4][5][6]1 kg spools cluster near 25[7][8]
Price range across brandsUSD/kg296-770 across brands and spool sizes; 3D4Makers recycled R-PEEK 296 at 750 g, IEMAI 3D 420 at 1 kg, LEHVOSS Luvocom 3F PEEK 9581 532 at 2 kg, 3DXTech ThermaX PEEK 770 at 500 g[4][5][6]19–30 across brands; ELEGOO 19, Polymaker Fiberon 30[7][8]
Market availability1–5Niche, a handful of specialist brands[4][5][3]Niche, a handful of specialist brands[7][8]
Spool sizes & diameters1.75 and 2.85 mm; 200 g to 2 kg spools[4][5][3]1.75 mm; 0.5 and 1 kg spools[8]
Typical applicationsAerospace brackets, semiconductor handling, sterilisable medical tooling and downhole parts[1]Stiff, dimensionally stable fixtures; the Fiberon grade is designed to be annealed for heat resistance[2]
Printing Parameters
Nozzle temperature°C380-400 (3DXTech printed-specimen conditions); Victrex quotes a 340-450 melt range for AM 450 FIL[1][3]Not documented
Bed temperature°C130–140 (3DXTech)[1]Not documented
Enclosure / chamber requirement1–5Actively heated chamber required[9][10]Not documented
Recommended chamber temperature°CNot less than 150 for semi-crystalline printing (Victrex AM 450 FIL); bed above 150[3]Not documented
Bed surface & adhesion aidNot documentedTextured PEI, satin or powder-coated sheets; on smooth PEI a glue stick acts as a release agent[11][12]
Warping tendency1–5Severe — heated chamber needed[9]Not documented
Bed-adhesion difficulty1–5Very difficult — special plates or slurry required[9]Needs the right surface or a thin adhesive — the problem is releasing the part, not sticking it[11][12]
Stringing / oozing tendency1–5Not documentedModerate — retraction tuning needed; Polymaker names stringing as PETG's common quirk[12]
Overall printing difficulty1–5Expert / industrial hardware only[9][10]Not documented
Extruder requirementAn all-metal hot end rated above 400 °C and a heated chamber; 3DXTech tests at 0.25 mm layer height on a 0.4 mm nozzle[1][9]Not documented
Hardware Wear & Reliability
Nozzle hardness required1–4Brass fine indefinitely for unfilled grades, but brass softens near these nozzle temperatures — hardened or plated hot ends are the norm[9]Hardened steel required[2]
Abrasiveness1–5Non-abrasive when unfilled[1]Highly abrasive — standard GF composite[2]
Nozzle clog risk1–5Moderate — needs dry filament and a clean nozzle; 3DXTech lists no special nozzle concerns but a mandatory 120 °C pre-dry before every print[13]Moderate — needs dry filament and a clean nozzle; Prusa lists higher risk of nozzle clogging for glass-filled composites[14]
Heat-creep / jam sensitivity1–5Not documentedSlightly sensitive[15]
Hotend requirementNot documentedNo special hot-end required[15]
Moisture Behaviour
Moisture absorption (hygroscopicity)1–5Not documentedModerate (0.3–0.8 %) — the PETG matrix reaches 0.40 % saturated at 25 °C / 55 % RH; no glass-filled grade publishes its own figure[11]
Equilibrium moisture content at ~50 % RH%0.45 at saturation, 23 °C (ISO 62); 0.55 at 100 °C[3]Not documented
Drying temperature & time120 °C for 5 h, target below 0.020 % moisture (Victrex AM 450 FIL)[3]Not documented
Symptoms when wetNot documentedBubbling and popping at the nozzle, stringing and a rough surface[16]
Effect of moisture on strengthNo 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[13]Polymaker 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[16]
Storage requirementNot documentedSealed with desiccant; Polymaker groups PETG with the highly hygroscopic materials[16][12]
Mechanical Properties
Tensile strength (XY)MPa60-100 (printed XY): Victrex AM 450 FIL 60-80 at yield and 3DXTech 100, both ISO 527; 98 at yield injection-moulded[1][3]59.9 ± 0.8 printed XY, ISO 527 (Fiberon PET-GF15)[2]
Young's modulusMPa3000-4000 (printed XY, ISO 527, Victrex AM 450 FIL); 3720 (3DXTech); 4000 injection-moulded[1][3]4144 ± 133 printed XY, ISO 527 (Fiberon PET-GF15)[2]
Elongation at break%28 (printed XY, ISO 527) — remarkably ductile for a high-temperature polymer[1]4.0 ± 0.5 printed XY, ISO 527 (Fiberon PET-GF15)[2]
Flexural strengthMPa130 (printed XY, ISO 178)[1]104.2 ± 2.4 printed XY, ISO 178 (Fiberon PET-GF15)[2]
Flexural modulusMPa2700 (printed XY, ISO 178)[1]3705 ± 85 printed XY, ISO 178 (Fiberon PET-GF15)[2]
Charpy impact, notchedkJ/m²6.0 (injection-moulded, ISO 179/1eA); unnotched does not break[3]8.7 ± 0.6 printed XY, ISO 179, notched (Fiberon PET-GF15)[2]
Other impact dataIzod notched 7.0 kJ/m2 injection-moulded (ISO 180/A). Printed anisotropy is extreme: VICTREX AM 200 on a Stratasys F900 gives Izod notched 1380-1530 J/m XZ against 30-62 J/m ZX (ASTM D256)[3][17]Charpy unnotched 27.2 ± 2.0 printed XY (Fiberon PET-GF15, ISO 179)[2]
Layer adhesion / Z tensileMPa20-85 at yield (printed ZX, ISO 527, Victrex AM 450 FIL); the spread is set by chamber temperature and weld quality[3]48.2 ± 0.3 printed Z, ISO 527 (Fiberon PET-GF15)[2]
Brittleness1–5Tough — absorbs impact, yields before breaking[1]Brittle — snaps with little warning; elongation 4.0 % in XY and 2.6 % in Z[2]
Hardness (scale-specific)Shore A / Shore D / RockwellShore D 84.5 (injection-moulded, ISO 868); Rockwell M100 / R125 on extruded PEEK stock (ASTM D785)[3][18]Not documented
Creep resistance / sustained load1–5Excellent — holds load for years. Victrex rates PEEK for long-term creep; injection-moulded flexural stress at 3.5 % strain falls only from 125 MPa at 23 °C to 85 MPa at 125 °C, and extruded stock is rated to 249 °C continuous[19][3][18]Below average — no GF-grade creep test; the CF grades sagged to 14.8–16.7 mm over 5 days at 1.25 kg against 17.1–20.4 mm unfilled[20][21][22]
Fatigue / repeated-flex resistance1–5Excellent — living hinges viable. Victrex rates PEEK for long-term fatigue as well as creep[19]Below average — no GF-grade S-N curve; elongation at break falls to 4.0 % in XY against 5.2–9.3 % unfilled[2][23]
Elasticity / flexibility1–5Rigid[1]Rigid[2]
Z strength as % of XY%71-84 (VICTREX AM 200 LMPAEK printed on the Stratasys F900 and Fortus 450mc, ZX against XZ tensile yield, ASTM D638); unfilled PEEK's own ZX spread is wider[17]80 (Fiberon PET-GF15, printed Z against XY tensile)[2]
Thermal Properties
HDT at 0.45 MPa°C140 (printed XY, ISO 75 at 0.45 MPa, 3DXTech)[1]81.6 as printed, 133.7 after annealing (ISO 75, 0.45 MPa)[2]
HDT at 1.8 MPa°C152 (unannealed, ISO 75-2/Af, Victrex AM 450 FIL); 160 on extruded stock (ASTM D648 at 264 psi)[3][18]71.8 as printed, 87.3 after annealing (ISO 75, 1.8 MPa)[2]
Glass transition (Tg)°C143 (DSC, 3DXTech); Victrex gives onset 143 and midpoint 150 (ISO 11357-2)[1][3]59.5 (DSC)[2]
Melting point / Vicat°C343 melting (ISO 11357-3, Victrex); VICTREX AM 200 LMPAEK melts at 303[3][17]231.6 melting (DSC); Vicat 232.6 (ISO 306)[2]
Continuous service temperature°C240 UL 746B relative thermal index, strength (RTI electrical 260, impact 180); Ensinger rates extruded PEEK stock at 249 long term[3][18]Not documented
Annealing responseNot documentedAnnealing lifts HDT at 0.45 MPa from 81.6 to 133.7 °C[2]
Thermal expansion (CTE)µm/m·K37.8 (extruded PEEK stock, 23-60 °C, ASTM E831; source states 2.1e-5 in/in/°F), rising to 41.9 at 60-100 °C and 55.8 at 100-150 °C[18]20 along the print bead and 63–74 in the build direction at 30 °C (30 wt% GF, large-format printed, TMA)[24]
Flammability / UL 94UL 94 V-0 at 1.5 mm on the base resin; glow-wire flammability index 960 °C at 2.0 mm (IEC 60695-2-12)[1][3]UL 94 HB at 1.5 mm (Fiberon PET-GF15)[2]
Environment & Chemical
Chemical resistanceOutstanding — resistant to almost all solvents and to steam sterilisation[1]Withstands acids, alkalis, oils and UV exposure[12]
Water / humidity resistance in service1–5Excellent — essentially unaffected; 0.45 % water at saturation and resistant to steam sterilisation[3][1]Not documented
Food contactNot documentedNot certified for food contact as filament[12]
Biodegradability / compostabilityNot documentedNot biodegradable[12]
RecyclabilityNot documentedNot accepted in household plastic collection[12]
Electrical & ESD propertiesNot documentedSurface resistivity above 10¹² ohm — insulating (Fiberon PET-GF15, ANSI/ESD S11.11)[2]
Health & Safety
Fume toxicity1–5Moderate — 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[25]Moderate — measurable VOCs and UFPs, ventilation advised[25]
Ventilation / filtration requirement1–5Ventilated room or enclosure recommended[25]Open a window / occasional ventilation[25]
Dust & fibre handling hazardNot documentedGlass fibre is bound in the matrix; avoid inhaling sanding dust[2]
Post-Processing
Sanding & machiningNot documentedSands poorly — the material is tough and gums rather than powders[15]
Gluing & solvent weldingNot documentedCyanoacrylate; no common solvent welds PETG cleanly[15]
Vapour / chemical smoothingNot documentedNo practical vapour smoothing[15]
Support material pairingNot documentedPrints its own supports; Polymaker rates PolyDissolve S1 for PETG[15]
Solvents & Solubility
Soluble in95–98 wt% sulphuric acid dissolves it — 10 g per 100 mL at 40–70 °C gives a dark red solution. Laboratory route only.[26][27]No common workshop solvent; dichloromethane — a carcinogen — dissolves the matrix surface, 1,2-dichloroethane destroys it in a week.[28][29]
Softened or crazed byConcentrated nitric, hydrofluoric, hydrobromic and hydriodic acids attack it; DCM, DMSO and THF swell thin-walled sections.[30][27]Acetone (+16 % weight over 1 year at 23 °C), ethyl acetate, toluene and DMF swell and soften it; methanol crazes it.[28]
Solvent welding & smoothing agentNone — no solvent softens PEEK, so parts are joined thermally or mechanically, never chemically.[30][27]Dichloromethane reaches only the resin, so the fibre is left standing proud of the surface. Controlled carcinogen.[29]

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. ThermaX PEEK Technical Data Sheet v3 3DXTech · 2026-08 · tds
  2. Fiberon PET-GF15 Technical Data Sheet V1.0 Polymaker · 2026-08 · tds
  3. VICTREX AM 450 FIL — datasheet Victrex · 2025-12 · tds
  4. 3DXTech product catalogue 3DXTech · 2026-08 · vendor
  5. 3D4Makers product catalogue 3D4Makers · 2026-08 · vendor
  6. IEMAI 3D PEEK 3D Printing Filament — store page IEMAI 3D · 2026-08 · vendor
  7. ELEGOO product catalogue ELEGOO · 2026-08 · vendor
  8. Polymaker product catalogue Polymaker · 2026-08 · vendor
  9. Prusament PEI 1010 Technical Datasheet v1.0 Prusa Polymers · 2024-09 · tds
  10. Prusament PEI 1010 — material page Prusa Polymers · 2026-08 · doc
  11. Prusament PETG Technical Datasheet v1.1 Prusa Polymers · 2022-02 · tds
  12. PETG — material basics Polymaker Wiki · 2026-08 · doc
  13. ThermaX PEEK — product page 3DXTech · 2026-08 · vendor
  14. Composite materials filled with carbon, kevlar or glass Prusa Knowledge Base · 2026-08 · doc
  15. PET and PETG — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  16. Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
  17. VICTREX AM 200 — FDM Material Data Sheet Stratasys · 2024-04 · tds
  18. TECAPEEK natural (PEEK) — stock shape properties Ensinger · 2026-08 · tds
  19. PEEK polymers — product overview Victrex · 2026-08 · doc
  20. Extrudr PETG vs PCTG vs XPETG-CF — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
  21. Prusament PETG-CF vs PETG V0 vs PETG — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
  22. BambuLab PETG Basic vs Translucent vs PETG-CF — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
  23. Mechanical Properties of Additively Manufactured Polymeric Materials — PLA and PETG — For Biomechanical Applications Polymers 16(13):1868 · 2024-06 · paper
  24. Effects of Fiber Orientation on the Coefficient of Thermal Expansion of Fiber-Filled Polymer Systems in Large Format Polymer Extrusion-Based Additive Manufacturing Materials 15(8):2764 · 2022-04 · paper
  25. 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
  26. 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
  27. Chemical resistance — resistance of Ensinger plastics to chemicals (DIN 50 014, 23/50) Ensinger · 2026-08 · tds
  28. Eastman Spectar copolyester — Chemical resistance (unstressed bars, 1 year at 23 °C) Eastman Chemical Company · 2026-08 · tds
  29. Improve your 3D prints with chemical smoothing Prusa Research · 2026-08 · doc
  30. What solvents are not compatible with PEEK? — fluidics technical FAQ IDEX Health & Science · 2026-08 · doc