3D Printing Info

Filament comparison

PA6-GF vs PCTG

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

Glass-fibre PA6 (PA6-GF) guidePCTG guide

2 selected · all documented properties

Open these two in the interactive comparisonMore PA6-GF comparisonsMore PCTG comparisons
PA6-GF vs PCTG — documented properties and sources
PropertyGlass-fibre PA6 (PA6-GF)PAPCTGPETG
Market snapshot
Listing priceUSD/kg; dated snapshots$59.98/kg median; $39.99–$130.00/kg across 6 dated product listings$34.99/kg median; $14.00–$50.67/kg across 5 dated product listings
Identity & Market
Base polymer / chemistryPA6 reinforced with chopped glass fibre — Polymaker's grade is 25 wt%[1][2]Poly(cyclohexylenedimethylene terephthalate) glycol — a copolyester with a higher cyclohexanedimethanol content than PETG[3][4]
Densityg/cm³1.14 (Bambu Lab) and 1.20 (Polymaker Fiberon), ISO 1183[2][1]1.23 (Extrudr, ASTM D792; 3DXTech, ISO 1183)[4][5]
Typical priceUSD/kg1 kg-equivalent spools span 40–130; the middle of the market is about 60[2][6][7]1 kg spools cluster near 34[8][5][9]
Price range across brandsUSD/kg40–130 across brands; SUNLU 40, YXPOLYER 45, Polymaker Fiberon and Bambu Lab 60, 3DXTech FibreX 87, Obsidian Nylon 6+GF 130[6][2][10][7][11]14–51 across brands; CHCKX 14 in a 10-roll bundle, Push Plastic 30, Proto-pasta 35 at 1 kg, 3DXTech 51[8][5][12]
Market availability1–5Stocked by most mainstream brands[2][6][10][7][11]Available from several mainstream brands[8][5][9][13]
Spool sizes & diameters1.75 and 2.85 mm; 0.5, 0.75 and 1 kg spools[6][10][2]1.75 and 2.85 mm; 0.5, 0.75, 1, 3 and 5 kg spools[8][9][5]
Typical applicationsStiff, heat-resistant structural parts where a matte finish and lower cost beat carbon fibre[2][1]Transparent covers, guards and impact-loaded parts where PETG cracks[3][4]
Printing Parameters
Nozzle temperature°C260–290 (Bambu Lab)[2]250–270 (Spectrum, Extrudr)[3][4]
Bed temperature°CNot documented60–100 (Spectrum)[3]
Enclosure / chamber requirement1–5Enclosure required (passive) — Bambu Lab specifies a 45–60 °C chamber[2]Open frame is fine — Spectrum and Extrudr both say a closed chamber is not necessary, Extrudr adds it helps on larger parts[3][4]
Recommended chamber temperature°C45–60 (Bambu Lab)[2]Not documented
Part cooling fanNot documentedUp to 100 % (Spectrum); 20–50 % (Extrudr)[3][4]
Bed surface & adhesion aidPEI sheet with a glue stick, or a dedicated adhesive such as Magigoo[14][15]Textured PEI, satin or powder-coated sheets; on smooth PEI a glue stick acts as a release agent[16][17]
Maximum volumetric flow (mm³/s; see test conditions)mm³/s10 at Bambu Lab's 130 mm/s cap on a 0.4 mm nozzle at 0.2 mm layer[2][18]1.6–16 at the 20–200 mm/s Extrudr rates the material for, on a 0.4 mm nozzle at 0.2 mm layer[4][18]
Bed-adhesion difficulty1–5Needs a specific surface plus adhesive[14]Needs the right surface or a thin adhesive — the problem is releasing the part, not sticking it[16][17]
Stringing / oozing tendency1–5Moderate — retraction tuning needed[15]Moderate — retraction tuning needed; Polymaker names stringing as PETG's common quirk[17]
Shrinkage%Not documented0.2–0.5 (Extrudr, ASTM D955)[4]
Overall printing difficulty1–5Expert / industrial hardware only[2][19]Easy — minor profile tuning[3][4]
Extruder requirement0.6 mm nozzle recommended by Bambu Lab; 0.4 and 0.8 also supported[2]Not documented
Hardware Wear & Reliability
Nozzle hardness required1–4Hardened steel required — Polymaker measures brass nozzle life at about 9 h on PA6-GF25 and recommends hardened steel or ruby[1]Brass fine indefinitely — Extrudr explicitly states no hardened nozzle is needed[4]
Abrasiveness1–5Highly abrasive — standard GF composite; Polymaker puts brass nozzle life at roughly 9 h on PA6-GF25[1]Non-abrasive[4]
Nozzle clog risk1–5Very high — frequent jams without careful setup[19]Low — 3DXTech lists no special nozzle concerns and no minimum layer height for PCTG, only a 65 °C pre-dry[20]
Heat-creep / jam sensitivity1–5Moderate — good heatbreak cooling needed[14]Slightly sensitive[21]
Hotend requirementMay require an all-metal hot end (Simplify3D)[14]No special hot-end required[21]
Moisture Behaviour
Moisture absorption (hygroscopicity)1–5Very high (>2 %) — 2.56 % saturated at 25 °C / 55 % RH (Bambu Lab) and 3.33 % equilibrium (Polymaker Fiberon), the highest in the dataset[2][1]Moderate (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][20]
Equilibrium moisture content at ~50 % RH%2.56 saturated at 25 °C / 55 % RH (Bambu Lab); 3.33 equilibrium (Polymaker Fiberon PA6-GF25)[2][1]Not documented
Drying temperature & time80 °C for 8–12 h (Bambu Lab)[2]Not documented
Symptoms when wetPopping and cracking during extrusion, then hard-to-diagnose defects[22]Bubbling and popping at the nozzle, stringing and a rough surface[19]
Effect of moisture on strengthPolymaker publishes dry and wet printed blocks for PA6-GF25 itself: at 4.57 % moisture tensile falls 80.1 → 40.2 MPa and modulus 5357 → 1794 MPa, while notched Charpy rises 10.0 → 28.0 kJ/m²[1][22]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[19]
Storage requirementSealed below 20 % RH with desiccant[19]Sealed with desiccant; Polymaker groups PETG with the highly hygroscopic materials[19][17]
Hydrolysis at melt temperaturePolymaker specifies an 80–100 °C dry and storage below 20 % RH; no molecular-weight loss figure is published, and the wet data it does publish is conditioning rather than melt hydrolysis[23][24]Not documented
Mechanical Properties
Tensile strength (XY)MPa75 ± 6 (Bambu Lab) and 80.1 ± 1.8 (Polymaker Fiberon, dry/annealed) printed XY, ISO 527; Fiberon falls to 40.2 ± 2.1 conditioned to 4.57 % moisture. Stratasys FDM PA6/66-GF30-FR gives 60.2-61.1 at break and 61.7-62.3 at yield printed XZ (ASTM D638)[2][1][25]43–44 at yield and 45–46 at break (ISO 527, injection-moulded resin data from Spectrum and Extrudr); 48 on My Tech Fun printed bars[3][4][26]
Young's modulusMPa2850 ± 260 (Bambu Lab) and 5357 ± 211 (Polymaker Fiberon, dry) printed XY, ISO 527; Fiberon falls to 1794 ± 84 conditioned. Stratasys FDM PA6/66-GF30-FR gives 5600-5830 printed XZ against 3050-3140 in ZX (ASTM D638)[2][1][25]Not documented
Elongation at break%2.4 ± 0.2 dry (Polymaker Fiberon) to 3.9 ± 0.8 (Bambu Lab) printed XY, ISO 527; the Fiberon grade rises to 4.2 ± 0.7 conditioned[2][1]215–220 at break on moulded specimens (ISO 527); 4.3–4.4 at yield[3][4]
Flexural modulusMPa3670 ± 140 printed XY, ISO 178 (Bambu Lab)[2]Not documented
Charpy impact, notchedkJ/m²10.0 ± 0.7 printed XY dry and 28.0 ± 1.0 conditioned, ISO 179 notched (Polymaker Fiberon); Bambu Lab 7.2 ± 2.3[1][2]93–94 notched Izod at 23 °C on moulded specimens (ISO 180); 3DXTech quotes 8 by ISO 180/A[3][4][5]
Other impact dataCharpy unnotched 27.2 ± 2.2 printed XY (Bambu Lab, ISO 179). Stratasys FDM PA6/66-GF30-FR gives Izod notched 74.6-77.1 J/m printed XZ against 17.2-22.1 in ZX (ASTM D256)[2][25]Izod 4.14 kJ/m² on My Tech Fun printed bars, against 3.37 for PETG on the same rig[26]
Layer adhesion / Z tensileMPa27 ± 5 (Bambu Lab) and 60.7 ± 1.1 (Polymaker Fiberon, dry) printed Z, ISO 527 — the two makers differ by more than a factor of two; Fiberon falls to 26.3 ± 1.5 conditioned. Stratasys FDM PA6/66-GF30-FR gives 23.7-24.4 at break printed ZX (ASTM D638)[2][1][25]21.6 on My Tech Fun 4×4 mm printed bars, against 32.9 for PETG[26]
Brittleness1–5Brittle — snaps with little warning; elongation at break 2.4 % in XY[1]Tough — absorbs impact, yields before breaking[3][4]
Hardness (scale-specific)Shore A / Shore D / RockwellRockwell M88 / R117 on extruded PA66-GF30 stock (ASTM D785)[27]69 Shore D measured by My Tech Fun, against 72 for PETG[26]
Creep resistance / sustained load1–5Good. Ensinger lists high creep resistance as a headline property of extruded PA66-GF30 stock; the rating is held below Excellent because equilibrium moisture uptake of 3.33 % softens the matrix in service[27][1]Below average — a 12 mm bar sagged to 19.4 mm over 5 days at 1.25 kg, slightly worse than PETG's 18.2[26]
Fatigue / repeated-flex resistance1–5Good. Ensinger lists high fatigue strength as a headline property of extruded PA66-GF30 stock[27]Good — 215 % elongation at break and 94 kJ/m² notched Izod on moulded specimens (Extrudr, Spectrum)[3][4]
Elasticity / flexibility1–5Rigid[2]Slightly flexible in thin sections[26]
Z strength as % of XY%36 (Bambu Lab) to 76 (Polymaker Fiberon), printed; Stratasys FDM PA6/66-GF30-FR gives 39-41 (ZX against XZ tensile at break, ASTM D638)[2][1][25]Not documented
Thermal Properties
HDT at 0.45 MPa°C182 (Bambu Lab) and 191 (Polymaker Fiberon), ISO 75 at 0.45 MPa. Stratasys FDM PA6/66-GF30-FR gives 161 printed XY and 185 XZ (ASTM D648 at 66 psi)[2][1][25]Not documented
HDT at 1.8 MPa°C157 (Polymaker Fiberon) and 158 (Bambu Lab), ISO 75 at 1.8 MPa[2][1]Not documented
Glass transition (Tg)°C67 (Bambu Lab) and 70.4 (Polymaker Fiberon), DSC; Stratasys measures 51.5 on FDM PA6/66-GF30-FR (ASTM D7426)[2][1][25]78 (3DXTech, DSC)[5]
Melting point / Vicat°C214.5 (Polymaker Fiberon) and 219 (Bambu Lab) melting, DSC; Vicat 210–212 (ISO 306)[2][1]Amorphous — no melting point; Vicat 88 (Spectrum, Extrudr)[3][4]
Continuous service temperature°CNot documented68 — loaded bars begin to move at this temperature, against 65 for PETG[26]
Thermal expansion (CTE)µm/m·K48.6 on extruded PA66-GF30 stock (ASTM D696; source states 2.7e-5 in/in/°F). Stratasys measures much higher on printed FDM PA6/66-GF30-FR — 95.4 over -20 to 5 °C and 214 over 25 to 80 °C in XY (ASTM E831)[27][25]Not documented
Flammability / UL 94Flammable; no UL 94 rating published for the grades surveyed[23]Flammable; no UL 94 rating published for standard grades[28]
Environment & Chemical
UV resistance1–5Months outdoors before embrittlement — unstabilised polyamide yellows under UV[15]Not documented
Chemical resistanceWithstands oils, fuels and alkalis[15]Withstands acids, alkalis, oils and UV exposure[17]
Water / humidity resistance in service1–5Absorbs water, properties shift[22]Good — minor absorption; Spectrum describes the polymer as hydrophobic[3]
Food contactNot food-contact certified as filament[15]Not certified for food contact as filament[17]
Biodegradability / compostabilityNot biodegradable[15]Not biodegradable[17]
RecyclabilityNot accepted in household plastic collection[15]Not accepted in household plastic collection[17]
Electrical & ESD propertiesSurface resistivity above 10¹² ohm — insulating (Polymaker Fiberon, ANSI/ESD S11.11)[1]Surface resistance above 10¹³ ohm/sq — insulating (3DXTech, ASTM D257)[5]
Health & Safety
Fume toxicity1–5Moderate — measurable VOCs and UFPs, ventilation advised[29]Moderate — measurable VOCs and UFPs, ventilation advised[29]
VOC emission rateµg/minUp to 180 caprolactam, the dominant VOC from nylon and the largest single-VOC rate in the study[29]Not documented
Ultrafine-particle emission rateparticles/min≈2 × 10⁸ median for nylon — low for particles despite the highest VOC mass measured[29]Not documented
Hazardous species emittedCaprolactam, at up to 180 µg/min from nylon filament[29]Not documented
Ventilation / filtration requirement1–5Ventilated room or enclosure recommended[29]Open a window / occasional ventilation[29]
Dust & fibre handling hazardGlass fibre is bound in the matrix; avoid inhaling sanding dust[1]Not documented
Post-Processing
Sanding & machiningSands poorly — gums rather than powders[14]Sands poorly — the material is tough and gums rather than powders[21]
Gluing & solvent weldingCyanoacrylate; no common solvent welds polyamide[14]Cyanoacrylate; no common solvent welds PETG cleanly[21]
Vapour / chemical smoothingNo practical vapour smoothing[14]No practical vapour smoothing[21]
Support material pairingNot documentedPrints its own supports; Polymaker rates PolyDissolve S1 for PETG[21]
Dimensional accuracy & detailNot documentedOptical clarity is the selling point; Extrudr recommends a layer height at most 50 % of nozzle diameter[4]
Solvents & Solubility
Soluble inFormic acid, phenol, m-cresol and hexafluoroisopropanol dissolve the matrix at 23 °C, leaving the fibre; laboratory reagents.[30]No common workshop solvent; Eastman's CHDM copolyester data shows 1,2-dichloroethane destroying it within a week.[31]
Softened or crazed byZinc chloride solutions stress-crack the nylon matrix, alcoholic calcium chloride dissolves it, mineral acids attack it.[30]Acetone, ethyl acetate, toluene and DMF swell and soften the copolyester; methanol crazes it (Eastman, 1 y at 23 °C).[31]
Solvent welding & smoothing agentNone — nylon's only solvents (formic acid, phenol, HFIP) degrade the part, and the fibre blocks surface flow anyway.[30]Dichloromethane brushed on is the only agent that smooths PETG — a controlled carcinogen, not workshop stock.[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. Fiberon PA6-GF25 Technical Data Sheet V1.1 Polymaker · 2024-12 · tds
  2. Bambu Filament Technical Data Sheet — PA6-GF Bambu Lab · 2026-08 · tds
  3. Spectrum Premium PCTG Technical Data Sheet Spectrum Filaments · 2026-08 · tds
  4. Extrudr PCTG technical data Extrudr · 2026-08 · tds
  5. MAX-G PCTG Technical Data Sheet 3DXTech · 2026-08 · tds
  6. Polymaker product catalogue Polymaker · 2026-08 · vendor
  7. SUNLU Nylon-6 Glass Fiber (PA6-GF) 3D Printer Filament 1 kg — product page SUNLU · 2026-08 · vendor
  8. Push Plastic product catalogue Push Plastic · 2026-08 · vendor
  9. Proto-pasta product catalogue Proto-pasta · 2026-08 · vendor
  10. 3DXTech product catalogue 3DXTech · 2026-08 · vendor
  11. YXPOLYER PA6-GF Black 1 kg — product page YXPOLYER · 2026-08 · vendor
  12. CHCKX 10KG Multicolor PCTG Filament bundle CHCKX (Amazon US) · 2026-08 · vendor
  13. Atomic Filament product catalogue Atomic Filament · 2026-08 · vendor
  14. Nylon — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  15. PA (Nylon) — material basics Polymaker Wiki · 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. Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
  20. MAX-G PCTG — product page (print recommendations) 3DXTech · 2026-08 · doc
  21. PET and PETG — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  22. Moisture Conditioning — effect on printed nylon properties Polymaker Wiki · 2026-08 · doc
  23. Fiberon PA6-CF20 Technical Data Sheet V1.1 Polymaker · 2024-12 · tds
  24. PolyMide CoPA Technical Data Sheet V5.4 (dry and wet status blocks) Polymaker · 2024-11 · tds
  25. FDM PA6/66-GF30-FR — Material Data Sheet Stratasys · 2026-07 · tds
  26. PCTG vs PETG comparison — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
  27. TECAMID 66 GF30 black (PA66-GF30) — stock shape properties Ensinger · 2026-08 · tds
  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. Ultramid Nylon Chemical Resistance guide (unmodified PA6 B27E and PA66 A27E) BASF · 2026-08 · tds
  31. Eastman Spectar copolyester — Chemical resistance (unstressed bars, 1 year at 23 °C) Eastman Chemical Company · 2026-08 · tds
  32. Improve your 3D prints with chemical smoothing Prusa Research · 2026-08 · doc