FabDigit

PA6/66

ISO 1874-1 PA6/66

PA6/66 is a copolymer of PA6 and PA66 monomers with a depressed melting point and easier processing than pure PA66, available unfilled and with 15–50 % glass, 20 % carbon fiber, mineral, lubricated, impact-modified, heat-stabilized, UV, V-0, ESD, FDA and high-modulus conditions.

Standard cost $$

Reference datasheet — PA6/66 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.

PA6/66 grades and fills

PA6/66 is supplied in 11 conditions, soft to hard.

Compare all 11 grades and fillsHide
Grade · open for datasheetBest forYield MPaTensile MPaElong. %Hardness
Low-melt hot-melt adhesive / tie-layer copolymer grade
High PA6-rich or ternary copolymer with Tm 130–170 °C used as adhesive powder, film tie-layer or textile fusible interlining.224030055 Shore D
Impact-modified / super-tough
Select for snap fits, cold-weather impact and vibration-loaded parts where ductility beats stiffness.4548150105 HRR
Internally lubricated bearing grade
Pick for gears, bushings, slides and cams needing low friction and low wear without external lubrication.60653078 Shore D
ESD / conductive
For electronics handling trays, fuel-line components and any part needing controlled surface resistivity.66701281 Shore D
Heat stabilized
Use for long-term hot-air service (engine bay, appliance) where unstabilized nylon would embrittle within weeks.72764580 Shore D
Mineral / talc filled
Use when isotropic shrinkage, low warpage and a paintable Class-A surface matter more than peak strength.856
flame retardant, UL 94 V-0
Required for connectors, breakers and electrical housings needing V-0 at 0.4–1.6 mm; halogen-free (melamine/phosphinate) or brominated versions.90485 Shore D
15% short glass fiber reinforced
Moderate stiffness boost with retained toughness and lower warpage than GF30; good for housings and clips.1155
30% short glass fiber reinforced
Workhorse structural grade: highest strength/stiffness-per-cost and HDT above 200 °C for brackets, covers and under-hood parts.1753.295 HRM
20% carbon fiber reinforced
Choose for light, stiff, low-warp parts with static-dissipative surface and improved wear over glass.1902.5
50% short glass fiber reinforced
Maximum stiffness/creep resistance for metal-replacement load-bearing parts; brittle and abrasive to tooling.2102.5

Supply forms, finishes and certifications

Ways PA6/66 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.

OptionWhat it isType
FDA
FDA / food-contact & potable-water compliantCertification
UV
UV / weather stabilizedGrade option
NATDefault
Unfilled / NaturalStandard supply

What is PA6/66?

PA6/66 is a copolymer of PA6 and PA66 monomers with a depressed melting point and easier processing than pure PA66, available unfilled and with 15–50 % glass, 20 % carbon fiber, mineral, lubricated, impact-modified, heat-stabilized, UV, V-0, ESD, FDA and high-modulus conditions. Engineers select it for fast-cycle, thin-wall injection molding and good toughness at 76 MPa tensile strength, 60 % elongation and 2.8 GPa modulus, in molded connectors, clips and housings. Maximum service temperature is about 90 °C and the polymer absorbs moisture, so dimensions and stiffness drift with conditioning; PA66 or PA6T serves where higher heat is required. PA6/66 has a density of 1.13 g/cm³ (0.0408 lb/in³), lighter than 62% of polymer grades. Its glass-transition temperature is 50°C (122 °F). PA6/66 has a yield strength of 72 MPa (10.4 ksi) and a tensile strength of 76 MPa (11 ksi) — stronger than 82% of polymer grades. Elongation at break is 60% and the elastic modulus is 2.8 GPa (0.406 Msi).

What is PA6/66 used for?

  • automotive connectors
  • cable ties
  • power tool housings
  • fasteners

Advantages

  • Readily welded — 78/100, better than 84% of polymer grades
  • High strength — 72 MPa (10.4 ksi), better than 82% of polymer grades

Limitations

  • Absorbs moisture — dry before molding — 1.8%, worse than 95% of polymer grades
  • Needs corrosion protection — 60/100, worse than 89% of polymer grades
  • High embodied carbon — 7.5 kg CO₂/kg, worse than 79% of polymer grades

PA6/66 properties

Typical room-temperature values; bars are the position among polymer grades.

Physical5

PA6/66 has a density of 1.13 g/cm³ (0.0408 lb/in³), lighter than 62% of polymer grades. Its glass-transition temperature is 50°C (122 °F).

Density1.13 g/cm³0.04 lb/in³
Melting Temperature (Tm)196°C385 °F
Glass Transition (Tg)50°C122 °F
Water Absorption (24 h)1.8%
Water Absorption (Saturation)9.5%

Mechanical14

PA6/66 has a yield strength of 72 MPa (10.4 ksi) and a tensile strength of 76 MPa (11 ksi) — stronger than 82% of polymer grades. Elongation at break is 60% and the elastic modulus is 2.8 GPa (0.406 Msi).

Elastic (Young's) Modulus2.8 GPa0.41 Msi
Shear Modulus1 GPa0.15 Msi
Poisson's Ratio0.39
Tensile Strength (Ultimate)76 MPa11 ksi
Yield Strength (0.2% offset)72 MPa10.4 ksi
Elongation at Break60%
Compressive Strength80 MPa11.6 ksi
Flexural Strength95 MPa13.8 ksi
Flexural Modulus2.7 GPa0.39 Msi
Shear Strength55 MPa8 ksi
Izod Impact, Notched55 J/m1 ft·lbf/in
Hardness, Shore D80 Shore D
Hardness, Rockwell M78 HRM
Hardness, Rockwell R118 HRR

Thermal11

PA6/66 is rated for continuous service to 90°C (194 °F). It conducts heat at 0.25 W/m·K (0.144 BTU/hr·ft·°F), better than 72% of polymer grades. Thermal expansion is 90 µm/m·K (50 µin/in·°F).

Thermal Conductivity0.25 W/m·K0.14 BTU/hr·ft·°F
Specific Heat Capacity1,700 J/kg·K0.41 BTU/lb·°F
Thermal Expansion (CTE, 20–100 °C)90 µm/m·K50 µin/in·°F
Max Service Temperature (continuous)90°C194 °F
Min Service Temperature-40°C-40 °F
Heat Deflection Temp. @ 0.45 MPa165°C329 °F
Heat Deflection Temp. @ 1.8 MPa60°C140 °F
Vicat Softening Point (B50)180°C356 °F
Flammability (UL 94)HB at 0.8–3.0 mm (unfilled, natural); V-2 achievable in some grades, V-0 requires flame-retardant compound
Limiting Oxygen Index24%
Max Service Temperature (short-term)150°C302 °F

Electrical7

PA6/66 is an electrical insulator with a dielectric strength of 25 kV/mm (635 V/mil) and a resistivity of 1×10¹² Ω·m.

Electrical Resistivity1×10¹² Ω·m3.94×10¹⁹ µΩ·in
Dielectric Strength25 kV/mm635 V/mil
Dielectric Constant (1 MHz)3.4
Dissipation Factor (1 MHz)0.03
Volume Resistivity1×10¹⁴ Ω·cm
Surface Resistivity1×10¹³ Ω
Comparative Tracking Index (CTI)600 V

Chemical & Environmental3

Corrosion resistance is good (60/100), worse than 89% of polymer grades. UV resistance is poor.

Corrosion ResistanceGood60/100
UV / Weathering ResistancePoor30/100
Chemical Resistance SummaryGood against fuels, oils, greases, aliphatic/aromatic hydrocarbons, alcohols and most alkalis; attacked by strong mineral acids, formic acid, phenols, cresols and hot concentrated ZnCl2/LiCl solutions; hydrolysis and stress cracking possible in hot water/glycol and with road salt.

Sustainability4

Producing a kilogram of PA6/66 takes about 122 MJ of energy and emits 7.5 kg of CO₂ — more than 74% of polymer grades. Typical recycled content is 0%.

Embodied Energy (primary production)122 MJ/kg52,451 BTU/lb
Embodied Carbon (primary production)7.5 kg CO₂/kg
Embodied Water450 L/kg53.9 gal/lb
Typical Recycled Content0%

Manufacturability8

PA6/66's machinability is good (62/100, better than 60% of polymer grades); weldability very good (78/100); formability good (60/100).

MachinabilityGood62/100
WeldabilityVery good78/100
Formability (cold)Good60/100
PolishabilityGood55/100
Mold Shrinkage1.4%
Melt Flow Rate25 g/10 min
Processing Melt Temperature (typ.)260°C500 °F
Mold Temperature (typ.)70°C158 °F

Common Calculations5

Specific Strength (UTS / density)calculated67 kN·m/kg
Specific Stiffness (E / density)calculated2.5 MN·m/kg
Modulus of Resiliencecalculated926 kJ/m³
Thermal Diffusivitycalculated0.1 mm²/s
Thermal Shock Resistance Indexcalculated0

Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.

Strength versus weight in the polymer family

Yield strength against density for every polymer grade FabDigit runs. PA6/66 is highlighted; hover a dot for its name, or open the interactive family chart.

0.1110100123Density (g/cm³)Yield strength (MPa) — log scalePA6/66

Working with PA6/66

Is PA6/66 easy to machine?

Machines like PA6/PA66 — sharp positive-rake tools, high speed with light feed and air/mist cooling; expect gummy chips, springback and dimensional drift as the part absorbs moisture after cutting.

Can PA6/66 be welded?

Excellent for hot-plate, ultrasonic, vibration, IR and laser welding; the depressed melting point makes it a preferred tie-layer/adhesive to PA6 and PA66 substrates, but material must be dry before welding.

Can PA6/66 be formed, bent or molded?

Dry to <0.10% moisture (80 °C, 4 h desiccant) before molding; melt 240–280 °C, mold 40–90 °C, shrinkage 1.0–1.8% unfilled and anisotropic when glass filled; low Tm gives short cycles and easy thin-wall fill.

PA6/66 chemical composition (wt %)

Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.

ElementSpec limit (wt %)Nominal
caprolactam (PA6 unit)ε-caprolactam derived amide repeat unit; ratio sets Tm and crystallinity70 – 9082
heat/UV stabilizers, lubricants, nucleanadditive package, grade dependent0 – 20.5
glass fiber0 for the default natural grade; 15/30/50 % in reinforced variants0 – 500
hexamethylenediamine-adipic acid salt (PAH salt comonomer≥ 10 (balance)

What surface finishes work on PA6/66?

Readily dyed, printed and paintable after flame/plasma or primer treatment; can be metallized/electroless plated with etching; condition finished parts in warm water to reach equilibrium moisture and final toughness.

Equivalent designations

Standards and trade names that resolve to PA6/66 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.

ISO
1874-1 PA6/66
Also called
Nylon 6/66

How much does PA6/66 cost?

PA6/66 is a standard-cost polymer ($$), cheaper than about 71% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.

PA6/66 — frequently asked

What is PA6/66 used for?

PA6/66 is typically used for automotive connectors, cable ties, power tool housings and fasteners. In short: fastest-cycling nylon copolymer; low-melt PA6/PA66 tie layer; easier-flowing PA66 substitute.

What is the yield strength of PA6/66?

PA6/66 has a typical yield strength of 72 MPa (10.4 ksi) and a tensile strength of 76 MPa (11 ksi) — stronger than 82% of polymer grades. Strength varies by condition: see the 11 listed tempers.

Is PA6/66 easy to machine?

Reasonably — machinability is rated good (62/100, better than 60% of polymer grades). Machines like PA6/PA66 — sharp positive-rake tools, high speed with light feed and air/mist cooling; expect gummy chips, springback and dimensional drift as the part absorbs moisture after cutting.

Can PA6/66 be welded?

Yes — weldability is rated very good (78/100). Excellent for hot-plate, ultrasonic, vibration, IR and laser welding; the depressed melting point makes it a preferred tie-layer/adhesive to PA6 and PA66 substrates, but material must be dry before welding.

What surface finishes work on PA6/66?

Readily dyed, printed and paintable after flame/plasma or primer treatment; can be metallized/electroless plated with etching; condition finished parts in warm water to reach equilibrium moisture and final toughness.

Can PA6/66 be formed, bent or molded?

Dry to <0.10% moisture (80 °C, 4 h desiccant) before molding; melt 240–280 °C, mold 40–90 °C, shrinkage 1.0–1.8% unfilled and anisotropic when glass filled; low Tm gives short cycles and easy thin-wall fill.

What is the maximum service temperature of PA6/66?

PA6/66 is rated for continuous use to about 90°C (194 °F), and briefly to 150°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.

How much does PA6/66 cost?

PA6/66 is a standard-cost polymer ($$), cheaper than about 71% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.

Sources

  1. ISO 1874-1 Plastics — Polyamide (PA) moulding and extrusion materials — Designation system — ISO (2010)
  2. ISO 527-2 / ISO 178 / ISO 75 test methods for plastics — ISO (2019)
  3. CAMPUS plastics database — PA6/66 copolymer grades — CWFG / CAMPUS consortium (2024)
  4. Ultramid C (PA6/66) product line datasheets — BASF (2023)
  5. ASM Engineered Materials Handbook Vol. 2 — Engineering Plastics — ASM International (1988)
  6. GB/T 21460 / GB/T 36260 — SAC (2018)

Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.