3D Printing Info

Filament comparison

PA6 vs PA6/66

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

PA6 (Nylon 6) guidePA66 (Nylon 66) guide

2 selected · all documented properties

Open these two in the interactive comparisonMore PA6 comparisonsMore PA6/66 comparisons
PA6 vs PA6/66 — documented properties and sources
PropertyPA6 (Nylon 6)PAPA66 (Nylon 66)PA
Market snapshot
Listing priceUSD/kg; dated snapshots$104.00/kg median; $38.99–$136.00/kg across 3 dated product listingsNot documented
Identity & Market
Base polymer / chemistryPolyamide 6, ring-opened from caprolactam — the most hygroscopic of the common nylons[1][2]Polyamide 66, condensed from hexamethylenediamine and adipic acid; melts around 40 °C above PA6[1]
Densityg/cm³1.06 (ISO 1183, 3DXTech iOn PA6 alloy)[3]1.14 (extruded unfilled PA66 stock)[4]
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[5][6]Not documented
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[5][6]Not documented
Market availability1–5Niche, a handful of specialist brands[5]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[5][7]
Spool sizes & diameters1.75 and 2.85 mm; 500 g and 750 g spools[5]Not documented
Typical applicationsWear parts, bushings and gears where PA6's toughness and abrasion resistance matter more than dimensional stability[1]Not documented
Printing Parameters
Nozzle temperature°C220–260 (Polymaker); 225–265 (Simplify3D)[1][8]Not documented
Bed temperature°C70–100 (Polymaker); 70–90 (Simplify3D)[1][8]Not documented
Enclosure / chamber requirement1–5Enclosure required (passive)[9][1]Enclosure required (passive)[1]
Part cooling fanPart cooling fan not required (Simplify3D)[8]Not documented
Bed surface & adhesion aidPEI sheet with a glue stick, or a dedicated adhesive such as Magigoo[8][1]Not documented
Bed-adhesion difficulty1–5Needs a specific surface plus adhesive[8][1]Not documented
Stringing / oozing tendency1–5Moderate — retraction tuning needed[1]Not documented
Overall printing difficulty1–5Advanced — enclosure, hardware upgrades, tuning; the filament must be kept dry throughout the print[1][10]Advanced — enclosure, hardware upgrades, tuning[1]
Hardware Wear & Reliability
Nozzle hardness required1–4Brass fine indefinitely for unfilled grades[1]Not documented
Abrasiveness1–5Non-abrasive when unfilled[1]Not documented
Nozzle clog risk1–5Very high — frequent jams without careful setup; wet nylon pops and cracks in the melt[11][10]Very high — frequent jams without careful setup[11][10]
Heat-creep / jam sensitivity1–5Moderate — good heatbreak cooling needed[8]Not documented
Hotend requirementMay require an all-metal hot end (Simplify3D)[8]Not documented
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[10][12]Very high (>2 %)[10]
Equilibrium moisture content at ~50 % RH%Not documented8.5 at saturation on extruded PA66 stock (ASTM D570) — the highest uptake of any polymer in this dataset[4]
Drying temperature & time100 °C for 8 h (Polymaker CoPA); storage below 20 % RH[9][13]Not documented
Symptoms when wetPopping and cracking during extrusion, then defects that Polymaker describes as very hard to diagnose[11]Not documented
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 %[9][11]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 %[9][11]
Storage requirementSealed below 20 % RH with desiccant; Polymaker says nylon often needs to stay in a dryer while printing[13][10]Not documented
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[9][13]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)[3][14]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 modulusMPa2110 (printed XY, ISO 527, 3DXTech iOn PA6 alloy); Stratasys FDM Nylon 6 conditioned gives 2232 printed XZ and 1817 ZX (ASTM D638)[3][14]2413 on extruded PA66 stock (ASTM D638; converted from 350,000 psi)[4]
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)[3][14]50 at break on extruded PA66 stock (ASTM D638)[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)[3][14]113.8 on extruded PA66 stock (ASTM D790; converted from 16,500 psi)[4]
Flexural modulusMPa2200 (printed XY, ISO 178, 3DXTech iOn PA6 alloy); Stratasys FDM Nylon 6 conditioned gives 2196 printed XZ and 1879 ZX (ASTM D790)[3][14]3034 on extruded PA66 stock (ASTM D790; converted from 440,000 psi)[4]
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[14]Izod 53 J/m on extruded PA66 stock, converted from 1.0 ft-lb/in (ASTM D256)[4]
Layer adhesion / Z tensileMPa36.5 ultimate and 28.9 at yield printed ZX (Stratasys FDM Nylon 6, conditioned 20 °C / 50 % RH, ASTM D638)[14]Not documented
Brittleness1–5Tough — absorbs impact, yields before breaking[1]Not documented
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[4]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 load1–5Moderate[1]Not documented
Fatigue / repeated-flex resistance1–5Excellent — living hinges viable[1]Excellent — living hinges viable[1]
Elasticity / flexibility1–5Semi-flexible[11]Semi-flexible[11]
Z strength as % of XY%54 (Stratasys FDM Nylon 6 conditioned, ZX against XZ ultimate tensile, ASTM D638); 59 on the yield figures[14]Not documented
Wear resistance & friction3DXTech sells a dedicated wear-resistant PA6 grade; abrasion resistance is the usual reason to choose PA6 over PA12[5]Wear 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°CNot documented232 on extruded PA66 stock (ASTM D648 at 66 psi; converted from 450 °F)[4]
HDT at 1.8 MPa°C93 (Stratasys FDM Nylon 6, conditioned, ASTM D648 at 264 psi)[14]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)°C105 (DSC, 3DXTech iOn PA6 alloy)[3]Not documented
Melting point / Vicat°CNot documented255 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·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[4]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 unfilled filament grades surveyed[3]UL 94 V-2 on extruded PA66 stock[4]
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]Not documented
Water / humidity resistance in service1–5Absorbs water, properties shift — a conditioned part is measurably softer and larger than the same part dry[11][9]Not documented
Food contactPolymaker notes medical-grade variants exist, but standard filament is not food-contact certified[1]Not documented
Biodegradability / compostabilityNot biodegradable[1]Not documented
RecyclabilityMechanically recyclable but not accepted in household plastic collection[1]Not documented
Electrical & ESD propertiesNot documentedVolume 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[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]Up to 180 caprolactam, the dominant VOC from nylon; total VOC reached nearly 200 µg/min, the highest of the nine filaments tested[2]
Ultrafine-particle emission rateparticles/min≈2 × 10⁸ median — low for ultrafine particles despite the highest VOC mass of any filament tested[2]≈2 × 10⁸ median — low for ultrafine particles despite the highest VOC mass of any filament tested[2]
Hazardous species emittedCaprolactam, at up to 180 µg/min from nylon filament — the largest single-VOC emission rate measured in the study[2]Caprolactam, at up to 180 µg/min from nylon filament — the largest single-VOC emission rate measured in the study[2]
Ventilation / filtration requirement1–5Ventilated room or enclosure recommended[2]Ventilated room or enclosure recommended[2]
Post-Processing
Sanding & machiningSands poorly — the toughness makes it gum rather than powder[8]Not documented
Gluing & solvent weldingCyanoacrylate; no common solvent welds polyamide[8]Not documented
Vapour / chemical smoothingNo practical vapour smoothing[8]Not documented
Support material pairingPVA dissolves cleanly against nylon; Polymaker sells a break-away PolySupport for PA12[8]Not documented
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[11]Not documented
Solvents & Solubility
Soluble inDissolved at 23 °C by formic acid above ~50 %, phenol, m-cresol, 96 % sulphuric acid or hexafluoroisopropanol — laboratory reagents.[15]Dissolved at 23 °C by formic acid above ~80 %, phenol, m-cresol, 96 % sulphuric acid or hexafluoroisopropanol — laboratory reagents.[15]
Softened or crazed byZinc chloride solutions stress-crack it — 10 % marginal, 37 % not resistant; alcoholic calcium chloride dissolves it.[15]Zinc chloride solutions stress-crack it — 10 % marginal, 37 % not resistant; alcoholic calcium chloride dissolves it.[15]
Solvent welding & smoothing agentNone — nylon's only solvents are formic acid, phenol and HFIP, all of which degrade the part they wet.[15]None — nylon's only solvents are formic acid, phenol and HFIP, all of which degrade the part they wet.[15]

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. iOn PA6-based Nylon Alloy Technical Data Sheet v2.0 3DXTech · 2026-08 · tds
  4. TECAMID 66 natural (PA66) — stock shape properties Ensinger · 2026-08 · tds
  5. 3DXTech product catalogue 3DXTech · 2026-08 · vendor
  6. YXPOLYER PA6 Black 1 kg — product page YXPOLYER · 2026-08 · vendor
  7. Polymaker product catalogue Polymaker · 2026-08 · vendor
  8. Nylon — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  9. PolyMide CoPA Technical Data Sheet V5.4 (dry and wet status blocks) Polymaker · 2024-11 · tds
  10. Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
  11. Moisture Conditioning — effect on printed nylon properties Polymaker Wiki · 2026-08 · doc
  12. Fiberon PA612-CF15 Technical Data Sheet V1.1 Polymaker · 2024-12 · tds
  13. PolyMide CoPA — Technical Data Sheet page Polymaker Wiki · 2026-08 · tds
  14. FDM Nylon 6 — data sheet (conditioned 20 °C / 50 % RH) Stratasys · 2017-11 · tds
  15. Ultramid Nylon Chemical Resistance guide (unmodified PA6 B27E and PA66 A27E) BASF · 2026-08 · tds