3D Printing Info

Filament comparison

PA6 vs PCTG

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

PA6 (Nylon 6) guidePCTG guide

2 selected · all documented properties

Open these two in the interactive comparisonMore PA6 comparisonsMore PCTG comparisons
PA6 vs PCTG — documented properties and sources
PropertyPA6 (Nylon 6)PAPCTGPETG
Market snapshot
Listing priceUSD/kg; dated snapshots$104.00/kg median; $38.99–$136.00/kg across 3 dated product listings$34.99/kg median; $14.00–$50.67/kg across 5 dated product listings
Identity & Market
Base polymer / chemistryPolyamide 6, ring-opened from caprolactam — the most hygroscopic of the common nylons[1][2]Poly(cyclohexylenedimethylene terephthalate) glycol — a copolyester with a higher cyclohexanedimethanol content than PETG[3][4]
Densityg/cm³1.06 (ISO 1183, 3DXTech iOn PA6 alloy)[5]1.23 (Extrudr, ASTM D792; 3DXTech, ISO 1183)[4][6]
Typical priceUSD/kg1 kg-equivalent spools span 39–136; the middle of the market is about 104, though budget unfilled PA6 has now arrived at 39[7][8]1 kg spools cluster near 34[9][6][10]
Price range across brandsUSD/kg39–136 across brands; YXPOLYER 39, 3DXTech iOn Nylon 6 Alloy 104, WearX Nylon 6 136. Unfilled PA6 filament stays rare — most PA6 reaches the market glass- or carbon-filled[7][8]14–51 across brands; CHCKX 14 in a 10-roll bundle, Push Plastic 30, Proto-pasta 35 at 1 kg, 3DXTech 51[9][6][11]
Market availability1–5Niche, a handful of specialist brands[7]Available from several mainstream brands[9][6][10][12]
Spool sizes & diameters1.75 and 2.85 mm; 500 g and 750 g spools[7]1.75 and 2.85 mm; 0.5, 0.75, 1, 3 and 5 kg spools[9][10][6]
Typical applicationsWear parts, bushings and gears where PA6's toughness and abrasion resistance matter more than dimensional stability[1]Transparent covers, guards and impact-loaded parts where PETG cracks[3][4]
Printing Parameters
Nozzle temperature°C220–260 (Polymaker); 225–265 (Simplify3D)[1][13]250–270 (Spectrum, Extrudr)[3][4]
Bed temperature°C70–100 (Polymaker); 70–90 (Simplify3D)[1][13]60–100 (Spectrum)[3]
Enclosure / chamber requirement1–5Enclosure required (passive)[14][1]Open frame is fine — Spectrum and Extrudr both say a closed chamber is not necessary, Extrudr adds it helps on larger parts[3][4]
Part cooling fanPart cooling fan not required (Simplify3D)[13]Up to 100 % (Spectrum); 20–50 % (Extrudr)[3][4]
Bed surface & adhesion aidPEI sheet with a glue stick, or a dedicated adhesive such as Magigoo[13][1]Textured PEI, satin or powder-coated sheets; on smooth PEI a glue stick acts as a release agent[15][16]
Maximum volumetric flow (mm³/s; see test conditions)mm³/sNot documented1.6–16 at the 20–200 mm/s Extrudr rates the material for, on a 0.4 mm nozzle at 0.2 mm layer[4][17]
Bed-adhesion difficulty1–5Needs a specific surface plus adhesive[13][1]Needs the right surface or a thin adhesive — the problem is releasing the part, not sticking it[15][16]
Stringing / oozing tendency1–5Moderate — retraction tuning needed[1]Moderate — retraction tuning needed; Polymaker names stringing as PETG's common quirk[16]
Shrinkage%Not documented0.2–0.5 (Extrudr, ASTM D955)[4]
Overall printing difficulty1–5Advanced — enclosure, hardware upgrades, tuning; the filament must be kept dry throughout the print[1][18]Easy — minor profile tuning[3][4]
Hardware Wear & Reliability
Nozzle hardness required1–4Brass fine indefinitely for unfilled grades[1]Brass fine indefinitely — Extrudr explicitly states no hardened nozzle is needed[4]
Abrasiveness1–5Non-abrasive when unfilled[1]Non-abrasive[4]
Nozzle clog risk1–5Very high — frequent jams without careful setup; wet nylon pops and cracks in the melt[19][18]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[13]Slightly sensitive[21]
Hotend requirementMay require an all-metal hot end (Simplify3D)[13]No special hot-end required[21]
Moisture Behaviour
Moisture absorption (hygroscopicity)1–5Very high (>2 %) — Polymaker groups nylon with PVA as the most moisture-prone class, and its own PA6-based composites reach 2.35–3.33 % equilibrium[18][22]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[15][20]
Drying temperature & time100 °C for 8 h (Polymaker CoPA); storage below 20 % RH[14][23]Not documented
Symptoms when wetPopping and cracking during extrusion, then defects that Polymaker describes as very hard to diagnose[19]Bubbling and popping at the nozzle, stringing and a rough surface[18]
Effect of moisture on strengthMeasured 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 %[14][19]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[18]
Storage requirementSealed below 20 % RH with desiccant; Polymaker says nylon often needs to stay in a dryer while printing[23][18]Sealed with desiccant; Polymaker groups PETG with the highly hygroscopic materials[18][16]
Hydrolysis at melt temperaturePolymaker requires a 100 °C dry for 8 h and storage below 20 % RH; no molecular-weight loss figure is published, and the published wet data is conditioning rather than melt hydrolysis[14][23]Not documented
Mechanical Properties
Tensile strength (XY)MPa62 at break (printed XY, ISO 527, 3DXTech iOn PA6 alloy); Stratasys FDM Nylon 6 conditioned to 20 °C / 50 % RH gives 67.6 ultimate and 49.3 at yield printed XZ (ASTM D638)[5][24]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][25]
Young's modulusMPa2110 (printed XY, ISO 527, 3DXTech iOn PA6 alloy); Stratasys FDM Nylon 6 conditioned gives 2232 printed XZ and 1817 ZX (ASTM D638)[5][24]Not documented
Elongation at break%9 at break (printed XY, ISO 527, 3DXTech iOn PA6 alloy); Stratasys FDM Nylon 6 conditioned gives 38 printed XZ against 3.2 in ZX (ASTM D638)[5][24]215–220 at break on moulded specimens (ISO 527); 4.3–4.4 at yield[3][4]
Flexural strengthMPa78 (printed XY, ISO 178, 3DXTech iOn PA6 alloy); Stratasys FDM Nylon 6 conditioned gives 97.2 printed XZ and 82 ZX (ASTM D790)[5][24]Not documented
Flexural modulusMPa2200 (printed XY, ISO 178, 3DXTech iOn PA6 alloy); Stratasys FDM Nylon 6 conditioned gives 2196 printed XZ and 1879 ZX (ASTM D790)[5][24]Not documented
Charpy impact, notchedkJ/m²Not documented93–94 notched Izod at 23 °C on moulded specimens (ISO 180); 3DXTech quotes 8 by ISO 180/A[3][4][6]
Other impact dataIzod notched 106 J/m printed XZ against 43 J/m in ZX; unnotched 2873 against 192 J/m (Stratasys FDM Nylon 6, conditioned 20 °C / 50 % RH, ASTM D256 Method A) — a 15x anisotropy unnotched[24]Izod 4.14 kJ/m² on My Tech Fun printed bars, against 3.37 for PETG on the same rig[25]
Layer adhesion / Z tensileMPa36.5 ultimate and 28.9 at yield printed ZX (Stratasys FDM Nylon 6, conditioned 20 °C / 50 % RH, ASTM D638)[24]21.6 on My Tech Fun 4×4 mm printed bars, against 32.9 for PETG[25]
Brittleness1–5Tough — absorbs impact, yields before breaking[1]Tough — absorbs impact, yields before breaking[3][4]
Hardness (scale-specific)Shore A / Shore D / RockwellShore D 86 and Rockwell 85 (108) — the source does not name the scales on extruded unfilled PA66 stock (ASTM D2240, D785); no figure is published for a PA6 filament[26]69 Shore D measured by My Tech Fun, against 72 for PETG[25]
Creep resistance / sustained load1–5Moderate[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[25]
Fatigue / repeated-flex resistance1–5Excellent — living hinges viable[1]Good — 215 % elongation at break and 94 kJ/m² notched Izod on moulded specimens (Extrudr, Spectrum)[3][4]
Elasticity / flexibility1–5Semi-flexible[19]Slightly flexible in thin sections[25]
Z strength as % of XY%54 (Stratasys FDM Nylon 6 conditioned, ZX against XZ ultimate tensile, ASTM D638); 59 on the yield figures[24]Not documented
Wear resistance & friction3DXTech sells a dedicated wear-resistant PA6 grade; abrasion resistance is the usual reason to choose PA6 over PA12[7]Not documented
Thermal Properties
HDT at 1.8 MPa°C93 (Stratasys FDM Nylon 6, conditioned, ASTM D648 at 264 psi)[24]Not documented
Glass transition (Tg)°C105 (DSC, 3DXTech iOn PA6 alloy)[5]78 (3DXTech, DSC)[6]
Melting point / Vicat°CNot documentedAmorphous — 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[25]
Thermal expansion (CTE)µm/m·K81.0 on extruded unfilled PA66 stock (ASTM D696; source states 4.5e-5 in/in/°F); no figure is published for a PA6 filament, and PA6 and PA66 expand almost identically[26]Not documented
Flammability / UL 94Flammable; no UL 94 rating published for the unfilled filament grades surveyed[5]Flammable; no UL 94 rating published for standard grades[27]
Environment & Chemical
UV resistance1–5Months outdoors before embrittlement — unstabilised polyamide yellows and chalks under UV[1]Not documented
Chemical resistanceWithstands oils, fuels and alkalis — the usual reason to choose a polyamide[1]Withstands acids, alkalis, oils and UV exposure[16]
Water / humidity resistance in service1–5Absorbs water, properties shift — a conditioned part is measurably softer and larger than the same part dry[19][14]Good — minor absorption; Spectrum describes the polymer as hydrophobic[3]
Food contactPolymaker notes medical-grade variants exist, but standard filament is not food-contact certified[1]Not certified for food contact as filament[16]
Biodegradability / compostabilityNot biodegradable[1]Not biodegradable[16]
RecyclabilityMechanically recyclable but not accepted in household plastic collection[1]Not accepted in household plastic collection[16]
Electrical & ESD propertiesNot documentedSurface resistance above 10¹³ ohm/sq — insulating (3DXTech, ASTM D257)[6]
Health & Safety
Fume toxicity1–5Moderate — measurable VOCs and UFPs, ventilation advised[2]Moderate — measurable VOCs and UFPs, ventilation advised[2]
VOC emission rateµg/minUp to 180 caprolactam, the dominant VOC from nylon; total VOC reached nearly 200 µg/min, the highest of the nine filaments tested[2]Not documented
Ultrafine-particle emission rateparticles/min≈2 × 10⁸ median — low for ultrafine particles despite the highest VOC mass of any filament tested[2]Not documented
Hazardous species emittedCaprolactam, at up to 180 µg/min from nylon filament — the largest single-VOC emission rate measured in the study[2]Not documented
Ventilation / filtration requirement1–5Ventilated room or enclosure recommended[2]Open a window / occasional ventilation[2]
Post-Processing
Sanding & machiningSands poorly — the toughness makes it gum rather than powder[13]Sands poorly — the material is tough and gums rather than powders[21]
Gluing & solvent weldingCyanoacrylate; no common solvent welds polyamide[13]Cyanoacrylate; no common solvent welds PETG cleanly[21]
Vapour / chemical smoothingNo practical vapour smoothing[13]No practical vapour smoothing[21]
Support material pairingPVA dissolves cleanly against nylon; Polymaker sells a break-away PolySupport for PA12[13]Prints its own supports; Polymaker rates PolyDissolve S1 for PETG[21]
Dimensional accuracy & detailParts grow as they absorb moisture after printing; Polymaker declines to publish a standard dimensional allowance because it depends on geometry and infill[19]Optical clarity is the selling point; Extrudr recommends a layer height at most 50 % of nozzle diameter[4]
Solvents & Solubility
Soluble inDissolved at 23 °C by formic acid above ~50 %, phenol, m-cresol, 96 % sulphuric acid or hexafluoroisopropanol — laboratory reagents.[28]No common workshop solvent; Eastman's CHDM copolyester data shows 1,2-dichloroethane destroying it within a week.[29]
Softened or crazed byZinc chloride solutions stress-crack it — 10 % marginal, 37 % not resistant; alcoholic calcium chloride dissolves it.[28]Acetone, ethyl acetate, toluene and DMF swell and soften the copolyester; methanol crazes it (Eastman, 1 y at 23 °C).[29]
Solvent welding & smoothing agentNone — nylon's only solvents are formic acid, phenol and HFIP, all of which degrade the part they wet.[28]Dichloromethane brushed on is the only agent that smooths PETG — a controlled carcinogen, not workshop stock.[30]

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. PA (Nylon) — material basics Polymaker Wiki · 2026-08 · doc
  2. 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
  3. Spectrum Premium PCTG Technical Data Sheet Spectrum Filaments · 2026-08 · tds
  4. Extrudr PCTG technical data Extrudr · 2026-08 · tds
  5. iOn PA6-based Nylon Alloy Technical Data Sheet v2.0 3DXTech · 2026-08 · tds
  6. MAX-G PCTG Technical Data Sheet 3DXTech · 2026-08 · tds
  7. 3DXTech product catalogue 3DXTech · 2026-08 · vendor
  8. YXPOLYER PA6 Black 1 kg — product page YXPOLYER · 2026-08 · vendor
  9. Push Plastic product catalogue Push Plastic · 2026-08 · vendor
  10. Proto-pasta product catalogue Proto-pasta · 2026-08 · vendor
  11. CHCKX 10KG Multicolor PCTG Filament bundle CHCKX (Amazon US) · 2026-08 · vendor
  12. Atomic Filament product catalogue Atomic Filament · 2026-08 · vendor
  13. Nylon — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  14. PolyMide CoPA Technical Data Sheet V5.4 (dry and wet status blocks) Polymaker · 2024-11 · tds
  15. Prusament PETG Technical Datasheet v1.1 Prusa Polymers · 2022-02 · tds
  16. PETG — material basics Polymaker Wiki · 2026-08 · doc
  17. Max volumetric speed Prusa Knowledge Base · 2026-08 · doc
  18. Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
  19. Moisture Conditioning — effect on printed nylon properties 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. Fiberon PA612-CF15 Technical Data Sheet V1.1 Polymaker · 2024-12 · tds
  23. PolyMide CoPA — Technical Data Sheet page Polymaker Wiki · 2026-08 · tds
  24. FDM Nylon 6 — data sheet (conditioned 20 °C / 50 % RH) Stratasys · 2017-11 · tds
  25. PCTG vs PETG comparison — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
  26. TECAMID 66 natural (PA66) — stock shape properties Ensinger · 2026-08 · tds
  27. Prusament PETG V0 Technical Datasheet Prusa Polymers · 2026-08 · tds
  28. Ultramid Nylon Chemical Resistance guide (unmodified PA6 B27E and PA66 A27E) BASF · 2026-08 · tds
  29. Eastman Spectar copolyester — Chemical resistance (unstressed bars, 1 year at 23 °C) Eastman Chemical Company · 2026-08 · tds
  30. Improve your 3D prints with chemical smoothing Prusa Research · 2026-08 · doc