3D Printing Info

Filament comparison

PA6/66 vs PSU

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

PA66 (Nylon 66) guidePSU guide

2 selected · all documented properties

Open these two in the interactive comparisonMore PA6/66 comparisonsMore PSU comparisons
PA6/66 vs PSU — documented properties and sources
PropertyPA66 (Nylon 66)PAPSUHIGHTEMP
Market snapshot
Listing priceUSD/kg; dated snapshotsNot documented$168.00/kg median; $168.00–$168.00/kg across 1 dated product listings
Identity & Market
Base polymer / chemistryPolyamide 66, condensed from hexamethylenediamine and adipic acid; melts around 40 °C above PA6[1]Polysulfone — the lowest-temperature and cheapest of the sulfone family[2]
Densityg/cm³1.14 (extruded unfilled PA66 stock)[3]1.24 (ISO 1183)[2]
Typical priceUSD/kgNot documented1 kg-equivalent spools cluster near 250[4]
Price range across brandsUSD/kgNot documented168-250 across formats; 250 g spool $42 (168/kg), 500 g $125 (250/kg) — 3DXTech is the only filament supplier found[4]
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[4][5]Special order, 1–2 makers worldwide[4]
Spool sizes & diametersNot documented1.75 mm; 250 g and 500 g spools[4]
Typical applicationsNot documentedTransparent high-temperature housings, medical trays and hot-water fittings[2]
Printing Parameters
Bed temperature°CNot documented120–140 (3DXTech)[2]
Enclosure / chamber requirement1–5Enclosure required (passive)[1]Actively heated chamber required[6][7]
Overall printing difficulty1–5Advanced — enclosure, hardware upgrades, tuning[1]Expert / industrial hardware only[6][7]
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[6]
Abrasiveness1–5Not documentedNon-abrasive when unfilled[2]
Nozzle clog risk1–5Very high — frequent jams without careful setup[8][9]Moderate — needs dry filament and a clean nozzle; 3DXTech lists no special nozzle concerns but a mandatory 120 °C pre-dry before every print[10]
Moisture Behaviour
Moisture absorption (hygroscopicity)1–5Very high (>2 %)[9]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]0.30 in 24 h on extruded stock (ASTM D570)[11]
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 %[12][8]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[10]
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]52 (printed XY, ISO 527, 3DXTech); 81 at break on extruded stock (ASTM D638)[2][11]
Young's modulusMPa2413 on extruded PA66 stock (ASTM D638; converted from 350,000 psi)[3]2100 (printed XY, ISO 527)[2]
Elongation at break%50 at break on extruded PA66 stock (ASTM D638)[3]8 (printed XY, ISO 527) against 50 on extruded stock — nearly three times PPSU's printed 3 %[2][13][11]
Flexural strengthMPa113.8 on extruded PA66 stock (ASTM D790; converted from 16,500 psi)[3]87 (printed XY, ISO 178)[2]
Flexural modulusMPa3034 on extruded PA66 stock (ASTM D790; converted from 440,000 psi)[3]2050 (printed XY, ISO 178)[2]
Other impact dataIzod 53 J/m on extruded PA66 stock, converted from 1.0 ft-lb/in (ASTM D256)[3]Izod notched 69 J/m on extruded PSU stock, converted from 1.3 ft-lb/in (ASTM D256)[11]
Brittleness1–5Not documentedModerate[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]Rockwell M120 on extruded PSU stock (ASTM D785)[11]
Creep resistance / sustained load1–5Not documentedGood. Ensinger lists high creep resistance as a headline property of extruded PSU stock, which is rated to 173 °C heat deflection at 1.8 MPa[11]
Fatigue / repeated-flex resistance1–5Excellent — living hinges viable[1]Not documented
Elasticity / flexibility1–5Semi-flexible[8]Rigid[2]
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]172 (printed XY, ISO 75 at 0.45 MPa, 3DXTech); 181 on extruded stock, converted from 358 °F at 66 psi[2][11]
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]174 on extruded PSU stock, converted from 345 °F at 264 psi (ASTM D648)[11]
Glass transition (Tg)°CNot documented187 (DSC, 3DXTech) and 185 on extruded stock (ASTM D3418), against 230 for PPSU[2][13][11]
Melting point / Vicat°C255 melting on extruded PA66 stock (ASTM D2133; converted from 491 °F)[3]Not documented
Continuous service temperature°C85 long term and 149 short term on extruded PA66 stock (converted from 185 °F and 300 °F)[3]141 long-term service on extruded PSU stock, converted from 285 °F[11]
Thermal expansion (CTE)µm/m·K81.0 (extruded PA66 stock, ASTM D696; source states 4.5e-5 in/in/°F)[3]55.8 (extruded PSU stock, ASTM D696; source states 3.1e-5 in/in/°F)[11]
Flammability / UL 94UL 94 V-2 on extruded PA66 stock[3]UL 94 V-0 on extruded PSU stock[11]
Environment & Chemical
Electrical & ESD propertiesVolume resistance 1e15 ohm-cm and dielectric constant 4 on extruded PA66 stock (ASTM D257, D150)[3]Surface resistance above 10¹³ ohm/sq — an insulator (IEC 60093)[2]
Health & Safety
Fume toxicity1–5Moderate — measurable VOCs and UFPs, ventilation advised[14]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[14]
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[14]Not documented
Ultrafine-particle emission rateparticles/min≈2 × 10⁸ median — low for ultrafine particles despite the highest VOC mass of any filament tested[14]Not documented
Hazardous species emittedCaprolactam, at up to 180 µg/min from nylon filament — the largest single-VOC emission rate measured in the study[14]Not documented
Ventilation / filtration requirement1–5Ventilated room or enclosure recommended[14]Ventilated room or enclosure recommended[14]
Solvents & Solubility
Soluble inDissolved at 23 °C by formic acid above ~80 %, phenol, m-cresol, 96 % sulphuric acid or hexafluoroisopropanol — laboratory reagents.[15]Chlorinated hydrocarbons — dichloromethane, chloroform — dissolve polysulfone; ketones and esters attack it as well.[16][17]
Softened or crazed byZinc chloride solutions stress-crack it — 10 % marginal, 37 % not resistant; alcoholic calcium chloride dissolves it.[15]Acetone, MEK, ethyl acetate, benzene and toluene craze or stress-crack it; methanol and isopropanol only marginally.[17][16]
Solvent welding & smoothing agentNone — nylon's only solvents are formic acid, phenol and HFIP, all of which degrade the part they wet.[15]Dichloromethane cement welds PSU and NMP softens residual resin. Both are laboratory reagents.[16]

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 PSU Technical Data Sheet v3 3DXTech · 2026-08 · tds
  3. TECAMID 66 natural (PA66) — stock shape properties Ensinger · 2026-08 · tds
  4. 3DXTech product catalogue 3DXTech · 2026-08 · vendor
  5. Polymaker product catalogue Polymaker · 2026-08 · vendor
  6. Prusament PEI 1010 Technical Datasheet v1.0 Prusa Polymers · 2024-09 · tds
  7. Prusament PEI 1010 — material page Prusa Polymers · 2026-08 · doc
  8. Moisture Conditioning — effect on printed nylon properties Polymaker Wiki · 2026-08 · doc
  9. Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
  10. THERMAX PSU — product page (print recommendations) 3DXTech · 2026-08 · doc
  11. TECASON S natural (PSU) — stock shape properties Ensinger · 2026-08 · tds
  12. PolyMide CoPA Technical Data Sheet V5.4 (dry and wet status blocks) Polymaker · 2024-11 · tds
  13. ThermaX PPSU Technical Data Sheet v3 3DXTech · 2026-08 · tds
  14. 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
  15. Ultramid Nylon Chemical Resistance guide (unmodified PA6 B27E and PA66 A27E) BASF · 2026-08 · tds
  16. Radel PPSU, Veradel PESU, Acudel modified PPSU Design Guide — environmental stress cracking tables Solvay Specialty Polymers · 2026-08 · tds
  17. Chemical resistance — resistance of Ensinger plastics to chemicals (DIN 50 014, 23/50) Ensinger · 2026-08 · tds