3D Printing Info

Filament comparison

PA6-GF vs PA6/66

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

Glass-fibre PA6 (PA6-GF) guidePA66 (Nylon 66) guide

2 selected · all documented properties

Open these two in the interactive comparisonMore PA6-GF comparisonsMore PA6/66 comparisons
PA6-GF vs PA6/66 — documented properties and sources
PropertyGlass-fibre PA6 (PA6-GF)PAPA66 (Nylon 66)PA
Market snapshot
Listing priceUSD/kg; dated snapshots$59.98/kg median; $39.99–$130.00/kg across 6 dated product listingsNot documented
Identity & Market
Base polymer / chemistryPA6 reinforced with chopped glass fibre — Polymaker's grade is 25 wt%[1][2]Polyamide 66, condensed from hexamethylenediamine and adipic acid; melts around 40 °C above PA6[3]
Densityg/cm³1.14 (Bambu Lab) and 1.20 (Polymaker Fiberon), ISO 1183[2][1]1.14 (extruded unfilled PA66 stock)[4]
Typical priceUSD/kg1 kg-equivalent spools span 40–130; the middle of the market is about 60[2][5][6]Not documented
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[5][2][7][6][8]Not documented
Market availability1–5Stocked by most mainstream brands[2][5][7][6][8]Special order, 1–2 makers worldwide — no unfilled PA66 filament appeared in any catalogue searched, and the 3DXTech nylon range offers PA6, PA12 and a 6/66 copolymer but no straight PA66[7][5]
Spool sizes & diameters1.75 and 2.85 mm; 0.5, 0.75 and 1 kg spools[5][7][2]Not documented
Typical applicationsStiff, heat-resistant structural parts where a matte finish and lower cost beat carbon fibre[2][1]Not documented
Printing Parameters
Nozzle temperature°C260–290 (Bambu Lab)[2]Not documented
Enclosure / chamber requirement1–5Enclosure required (passive) — Bambu Lab specifies a 45–60 °C chamber[2]Enclosure required (passive)[3]
Recommended chamber temperature°C45–60 (Bambu Lab)[2]Not documented
Bed surface & adhesion aidPEI sheet with a glue stick, or a dedicated adhesive such as Magigoo[9][3]Not documented
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][10]Not documented
Bed-adhesion difficulty1–5Needs a specific surface plus adhesive[9]Not documented
Stringing / oozing tendency1–5Moderate — retraction tuning needed[3]Not documented
Overall printing difficulty1–5Expert / industrial hardware only[2][11]Advanced — enclosure, hardware upgrades, tuning[3]
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]Not documented
Abrasiveness1–5Highly abrasive — standard GF composite; Polymaker puts brass nozzle life at roughly 9 h on PA6-GF25[1]Not documented
Nozzle clog risk1–5Very high — frequent jams without careful setup[11]Very high — frequent jams without careful setup[12][11]
Heat-creep / jam sensitivity1–5Moderate — good heatbreak cooling needed[9]Not documented
Hotend requirementMay require an all-metal hot end (Simplify3D)[9]Not documented
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]Very high (>2 %)[11]
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]8.5 at saturation on extruded PA66 stock (ASTM D570) — the highest uptake of any polymer in this dataset[4]
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[12]Not documented
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][12]Measured dry against wet on printed specimens at 6.16 % moisture (Polymaker CoPA): tensile 78.0 → 34.3 MPa, Young's modulus 2703 → 724 MPa, flexural strength 109.8 → 22.6 MPa, while notched Charpy rises 6.9 → 27.7 kJ/m² and elongation 12.7 → 13.2 %[13][12]
Storage requirementSealed below 20 % RH with desiccant[11]Not documented
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[14][13]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][15]82.7 at yield and 84.8 at break on extruded PA66 stock (ASTM D638; converted from 12,000 and 12,300 psi) — no printed figure exists because no unfilled PA66 filament was found[4]
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][15]2413 on extruded PA66 stock (ASTM D638; converted from 350,000 psi)[4]
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]50 at break on extruded PA66 stock (ASTM D638)[4]
Flexural strengthMPaNot documented113.8 on extruded PA66 stock (ASTM D790; converted from 16,500 psi)[4]
Flexural modulusMPa3670 ± 140 printed XY, ISO 178 (Bambu Lab)[2]3034 on extruded PA66 stock (ASTM D790; converted from 440,000 psi)[4]
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]Not documented
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][15]Izod 53 J/m on extruded PA66 stock, converted from 1.0 ft-lb/in (ASTM D256)[4]
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][15]Not documented
Brittleness1–5Brittle — snaps with little warning; elongation at break 2.4 % in XY[1]Not documented
Hardness (scale-specific)Shore A / Shore D / RockwellRockwell M88 / R117 on extruded PA66-GF30 stock (ASTM D785)[16]Shore D 86 and Rockwell 85 (108) — the source does not name the scales on extruded PA66 stock (ASTM D2240, D785)[4]
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[16][1]Not documented
Fatigue / repeated-flex resistance1–5Good. Ensinger lists high fatigue strength as a headline property of extruded PA66-GF30 stock[16]Excellent — living hinges viable[3]
Elasticity / flexibility1–5Rigid[2]Semi-flexible[12]
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][15]Not documented
Wear resistance & frictionNot documentedWear factor 200e-10 in3*min/(ft*lb*h) on extruded PA66 stock (ASTM D3702); Ensinger lists very good slide and wear properties[4]
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][15]232 on extruded PA66 stock (ASTM D648 at 66 psi; converted from 450 °F)[4]
HDT at 1.8 MPa°C157 (Polymaker Fiberon) and 158 (Bambu Lab), ISO 75 at 1.8 MPa[2][1]90 on extruded PA66 stock (ASTM D648 at 264 psi; converted from 194 °F) — the gap to the 0.45 MPa figure is the widest in the dataset[4]
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][15]Not documented
Melting point / Vicat°C214.5 (Polymaker Fiberon) and 219 (Bambu Lab) melting, DSC; Vicat 210–212 (ISO 306)[2][1]255 melting on extruded PA66 stock (ASTM D2133; converted from 491 °F)[4]
Continuous service temperature°CNot documented85 long term and 149 short term on extruded PA66 stock (converted from 185 °F and 300 °F)[4]
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)[16][15]81.0 (extruded PA66 stock, ASTM D696; source states 4.5e-5 in/in/°F)[4]
Flammability / UL 94Flammable; no UL 94 rating published for the grades surveyed[14]UL 94 V-2 on extruded PA66 stock[4]
Environment & Chemical
UV resistance1–5Months outdoors before embrittlement — unstabilised polyamide yellows under UV[3]Not documented
Chemical resistanceWithstands oils, fuels and alkalis[3]Not documented
Water / humidity resistance in service1–5Absorbs water, properties shift[12]Not documented
Food contactNot food-contact certified as filament[3]Not documented
Biodegradability / compostabilityNot biodegradable[3]Not documented
RecyclabilityNot accepted in household plastic collection[3]Not documented
Electrical & ESD propertiesSurface resistivity above 10¹² ohm — insulating (Polymaker Fiberon, ANSI/ESD S11.11)[1]Volume resistance 1e15 ohm-cm and dielectric constant 4 on extruded PA66 stock (ASTM D257, D150)[4]
Health & Safety
Fume toxicity1–5Moderate — measurable VOCs and UFPs, ventilation advised[17]Moderate — measurable VOCs and UFPs, ventilation advised[17]
VOC emission rateµg/minUp to 180 caprolactam, the dominant VOC from nylon and the largest single-VOC rate in the study[17]Up to 180 caprolactam, the dominant VOC from nylon; total VOC reached nearly 200 µg/min, the highest of the nine filaments tested[17]
Ultrafine-particle emission rateparticles/min≈2 × 10⁸ median for nylon — low for particles despite the highest VOC mass measured[17]≈2 × 10⁸ median — low for ultrafine particles despite the highest VOC mass of any filament tested[17]
Hazardous species emittedCaprolactam, at up to 180 µg/min from nylon filament[17]Caprolactam, at up to 180 µg/min from nylon filament — the largest single-VOC emission rate measured in the study[17]
Ventilation / filtration requirement1–5Ventilated room or enclosure recommended[17]Ventilated room or enclosure recommended[17]
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[9]Not documented
Gluing & solvent weldingCyanoacrylate; no common solvent welds polyamide[9]Not documented
Vapour / chemical smoothingNo practical vapour smoothing[9]Not documented
Solvents & Solubility
Soluble inFormic acid, phenol, m-cresol and hexafluoroisopropanol dissolve the matrix at 23 °C, leaving the fibre; laboratory reagents.[18]Dissolved at 23 °C by formic acid above ~80 %, phenol, m-cresol, 96 % sulphuric acid or hexafluoroisopropanol — laboratory reagents.[18]
Softened or crazed byZinc chloride solutions stress-crack the nylon matrix, alcoholic calcium chloride dissolves it, mineral acids attack it.[18]Zinc chloride solutions stress-crack it — 10 % marginal, 37 % not resistant; alcoholic calcium chloride dissolves it.[18]
Solvent welding & smoothing agentNone — nylon's only solvents (formic acid, phenol, HFIP) degrade the part, and the fibre blocks surface flow anyway.[18]None — nylon's only solvents are formic acid, phenol and HFIP, all of which degrade the part they wet.[18]

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. PA (Nylon) — material basics Polymaker Wiki · 2026-08 · doc
  4. TECAMID 66 natural (PA66) — stock shape properties Ensinger · 2026-08 · tds
  5. Polymaker product catalogue Polymaker · 2026-08 · vendor
  6. SUNLU Nylon-6 Glass Fiber (PA6-GF) 3D Printer Filament 1 kg — product page SUNLU · 2026-08 · vendor
  7. 3DXTech product catalogue 3DXTech · 2026-08 · vendor
  8. YXPOLYER PA6-GF Black 1 kg — product page YXPOLYER · 2026-08 · vendor
  9. Nylon — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  10. Max volumetric speed Prusa Knowledge Base · 2026-08 · doc
  11. Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
  12. Moisture Conditioning — effect on printed nylon properties Polymaker Wiki · 2026-08 · doc
  13. PolyMide CoPA Technical Data Sheet V5.4 (dry and wet status blocks) Polymaker · 2024-11 · tds
  14. Fiberon PA6-CF20 Technical Data Sheet V1.1 Polymaker · 2024-12 · tds
  15. FDM PA6/66-GF30-FR — Material Data Sheet Stratasys · 2026-07 · tds
  16. TECAMID 66 GF30 black (PA66-GF30) — stock shape properties Ensinger · 2026-08 · tds
  17. 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
  18. Ultramid Nylon Chemical Resistance guide (unmodified PA6 B27E and PA66 A27E) BASF · 2026-08 · tds