3D Printing Info

Filament comparison

PA6/66 vs PEEK

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

PA66 (Nylon 66) guidePEEK guide

2 selected · all documented properties

Open these two in the interactive comparisonMore PA6/66 comparisonsMore PEEK comparisons
PA6/66 vs PEEK — documented properties and sources
PropertyPA66 (Nylon 66)PAPEEKHIGHTEMP
Market snapshot
Listing priceUSD/kg; dated snapshotsNot documented$531.87/kg median; $296.14–$770.00/kg across 5 dated product listings
Identity & Market
Base polymer / chemistryPolyamide 66, condensed from hexamethylenediamine and adipic acid; melts around 40 °C above PA6[1]Polyether ether ketone — a semi-crystalline polyaryletherketone[2]
Densityg/cm³1.14 (extruded unfilled PA66 stock)[3]1.30 (ISO 1183)[2][4]
Typical priceUSD/kgNot documented1 kg-equivalent spools span 296–770; the middle of the market is about 532[5][6][7]
Price range across brandsUSD/kgNot documented296-770 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[5][6][7]
Market availability1–5Special 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][8]Niche, a handful of specialist brands[5][6][4]
Spool sizes & diametersNot documented1.75 and 2.85 mm; 200 g to 2 kg spools[5][6][4]
Typical applicationsNot documentedAerospace brackets, semiconductor handling, sterilisable medical tooling and downhole parts[2]
Printing Parameters
Nozzle temperature°CNot documented380-400 (3DXTech printed-specimen conditions); Victrex quotes a 340-450 melt range for AM 450 FIL[2][4]
Bed temperature°CNot documented130–140 (3DXTech)[2]
Enclosure / chamber requirement1–5Enclosure required (passive)[1]Actively heated chamber required[9][10]
Recommended chamber temperature°CNot documentedNot less than 150 for semi-crystalline printing (Victrex AM 450 FIL); bed above 150[4]
Warping tendency1–5Not documentedSevere — heated chamber needed[9]
Bed-adhesion difficulty1–5Not documentedVery difficult — special plates or slurry required[9]
Overall printing difficulty1–5Advanced — enclosure, hardware upgrades, tuning[1]Expert / industrial hardware only[9][10]
Extruder requirementNot documentedAn 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[2][9]
Hardware Wear & Reliability
Nozzle hardness required1–4Not documentedBrass fine indefinitely for unfilled grades, but brass softens near these nozzle temperatures — hardened or plated hot ends are the norm[9]
Abrasiveness1–5Not documentedNon-abrasive when unfilled[2]
Nozzle clog risk1–5Very high — frequent jams without careful setup[11][12]Moderate — needs dry filament and a clean nozzle; 3DXTech lists no special nozzle concerns but a mandatory 120 °C pre-dry before every print[13]
Moisture Behaviour
Moisture absorption (hygroscopicity)1–5Very high (>2 %)[12]Not documented
Equilibrium moisture content at ~50 % RH%8.5 at saturation on extruded PA66 stock (ASTM D570) — the highest uptake of any polymer in this dataset[3]0.45 at saturation, 23 °C (ISO 62); 0.55 at 100 °C[4]
Drying temperature & timeNot documented120 °C for 5 h, target below 0.020 % moisture (Victrex AM 450 FIL)[4]
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][11]No 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]
Mechanical Properties
Tensile strength (XY)MPa82.7 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[3]60-100 (printed XY): Victrex AM 450 FIL 60-80 at yield and 3DXTech 100, both ISO 527; 98 at yield injection-moulded[2][4]
Young's modulusMPa2413 on extruded PA66 stock (ASTM D638; converted from 350,000 psi)[3]3000-4000 (printed XY, ISO 527, Victrex AM 450 FIL); 3720 (3DXTech); 4000 injection-moulded[2][4]
Elongation at break%50 at break on extruded PA66 stock (ASTM D638)[3]28 (printed XY, ISO 527) — remarkably ductile for a high-temperature polymer[2]
Flexural strengthMPa113.8 on extruded PA66 stock (ASTM D790; converted from 16,500 psi)[3]130 (printed XY, ISO 178)[2]
Flexural modulusMPa3034 on extruded PA66 stock (ASTM D790; converted from 440,000 psi)[3]2700 (printed XY, ISO 178)[2]
Charpy impact, notchedkJ/m²Not documented6.0 (injection-moulded, ISO 179/1eA); unnotched does not break[4]
Other impact dataIzod 53 J/m on extruded PA66 stock, converted from 1.0 ft-lb/in (ASTM D256)[3]Izod 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)[4][15]
Layer adhesion / Z tensileMPaNot documented20-85 at yield (printed ZX, ISO 527, Victrex AM 450 FIL); the spread is set by chamber temperature and weld quality[4]
Brittleness1–5Not documentedTough — absorbs impact, yields before breaking[2]
Hardness (scale-specific)Shore A / Shore D / RockwellShore D 86 and Rockwell 85 (108) — the source does not name the scales on extruded PA66 stock (ASTM D2240, D785)[3]Shore D 84.5 (injection-moulded, ISO 868); Rockwell M100 / R125 on extruded PEEK stock (ASTM D785)[4][16]
Creep resistance / sustained load1–5Not documentedExcellent — 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[17][4][16]
Fatigue / repeated-flex resistance1–5Excellent — living hinges viable[1]Excellent — living hinges viable. Victrex rates PEEK for long-term fatigue as well as creep[17]
Elasticity / flexibility1–5Semi-flexible[11]Rigid[2]
Z strength as % of XY%Not documented71-84 (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[15]
Wear resistance & frictionWear factor 200e-10 in3*min/(ft*lb*h) on extruded PA66 stock (ASTM D3702); Ensinger lists very good slide and wear properties[3]Not documented
Thermal Properties
HDT at 0.45 MPa°C232 on extruded PA66 stock (ASTM D648 at 66 psi; converted from 450 °F)[3]140 (printed XY, ISO 75 at 0.45 MPa, 3DXTech)[2]
HDT at 1.8 MPa°C90 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[3]152 (unannealed, ISO 75-2/Af, Victrex AM 450 FIL); 160 on extruded stock (ASTM D648 at 264 psi)[4][16]
Glass transition (Tg)°CNot documented143 (DSC, 3DXTech); Victrex gives onset 143 and midpoint 150 (ISO 11357-2)[2][4]
Melting point / Vicat°C255 melting on extruded PA66 stock (ASTM D2133; converted from 491 °F)[3]343 melting (ISO 11357-3, Victrex); VICTREX AM 200 LMPAEK melts at 303[4][15]
Continuous service temperature°C85 long term and 149 short term on extruded PA66 stock (converted from 185 °F and 300 °F)[3]240 UL 746B relative thermal index, strength (RTI electrical 260, impact 180); Ensinger rates extruded PEEK stock at 249 long term[4][16]
Thermal expansion (CTE)µm/m·K81.0 (extruded PA66 stock, ASTM D696; source states 4.5e-5 in/in/°F)[3]37.8 (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[16]
Flammability / UL 94UL 94 V-2 on extruded PA66 stock[3]UL 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)[2][4]
Environment & Chemical
Chemical resistanceNot documentedOutstanding — resistant to almost all solvents and to steam sterilisation[2]
Water / humidity resistance in service1–5Not documentedExcellent — essentially unaffected; 0.45 % water at saturation and resistant to steam sterilisation[4][2]
Electrical & ESD propertiesVolume resistance 1e15 ohm-cm and dielectric constant 4 on extruded PA66 stock (ASTM D257, D150)[3]Not documented
Health & Safety
Fume toxicity1–5Moderate — measurable VOCs and UFPs, ventilation advised[18]Moderate — 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[18]
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[18]Not documented
Ultrafine-particle emission rateparticles/min≈2 × 10⁸ median — low for ultrafine particles despite the highest VOC mass of any filament tested[18]Not documented
Hazardous species emittedCaprolactam, at up to 180 µg/min from nylon filament — the largest single-VOC emission rate measured in the study[18]Not documented
Ventilation / filtration requirement1–5Ventilated room or enclosure recommended[18]Ventilated room or enclosure recommended[18]
Solvents & Solubility
Soluble inDissolved at 23 °C by formic acid above ~80 %, phenol, m-cresol, 96 % sulphuric acid or hexafluoroisopropanol — laboratory reagents.[19]95–98 wt% sulphuric acid dissolves it — 10 g per 100 mL at 40–70 °C gives a dark red solution. Laboratory route only.[20][21]
Softened or crazed byZinc chloride solutions stress-crack it — 10 % marginal, 37 % not resistant; alcoholic calcium chloride dissolves it.[19]Concentrated nitric, hydrofluoric, hydrobromic and hydriodic acids attack it; DCM, DMSO and THF swell thin-walled sections.[22][21]
Solvent welding & smoothing agentNone — nylon's only solvents are formic acid, phenol and HFIP, all of which degrade the part they wet.[19]None — no solvent softens PEEK, so parts are joined thermally or mechanically, never chemically.[22][21]

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. ThermaX PEEK Technical Data Sheet v3 3DXTech · 2026-08 · tds
  3. TECAMID 66 natural (PA66) — stock shape properties Ensinger · 2026-08 · tds
  4. VICTREX AM 450 FIL — datasheet Victrex · 2025-12 · tds
  5. 3DXTech product catalogue 3DXTech · 2026-08 · vendor
  6. 3D4Makers product catalogue 3D4Makers · 2026-08 · vendor
  7. IEMAI 3D PEEK 3D Printing Filament — store page IEMAI 3D · 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. Moisture Conditioning — effect on printed nylon properties Polymaker Wiki · 2026-08 · doc
  12. Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
  13. ThermaX PEEK — product page 3DXTech · 2026-08 · vendor
  14. PolyMide CoPA Technical Data Sheet V5.4 (dry and wet status blocks) Polymaker · 2024-11 · tds
  15. VICTREX AM 200 — FDM Material Data Sheet Stratasys · 2024-04 · tds
  16. TECAPEEK natural (PEEK) — stock shape properties Ensinger · 2026-08 · tds
  17. PEEK polymers — product overview Victrex · 2026-08 · doc
  18. 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
  19. Ultramid Nylon Chemical Resistance guide (unmodified PA6 B27E and PA66 A27E) BASF · 2026-08 · tds
  20. 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
  21. Chemical resistance — resistance of Ensinger plastics to chemicals (DIN 50 014, 23/50) Ensinger · 2026-08 · tds
  22. What solvents are not compatible with PEEK? — fluidics technical FAQ IDEX Health & Science · 2026-08 · doc