PA66
also Stanyl, Ultramid A
PA66 is a highly crystalline polyamide condensed from hexamethylenediamine and adipic acid (Zytel, Ultramid A), melting at 260–265 °C and stiffer, more heat-resistant and more wear- and oil-resistant than PA6.
PA66 grades and fills
PA66 is supplied in 12 conditions, soft to hard.
Compare all 12 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
Impact modified / super tough | Rubber-toughened PA66 for parts needing high notched and cold impact (housings, snap-fits, sporting goods). | 50 | 52 | 60 | 110 HRR |
PTFE lubricated | 15–20 % PTFE (sometimes with silicone oil) for dry-running bushings, slides and gears with low friction and wear. | 62 | 62 | 15 | 79 Shore D |
ESD / conductive | Use where static dissipation (10^4–10^9 Ω surface) is required, e.g. fuel-system and electronics handling parts. | 70 | 70 | 6 | 82 Shore D |
Flame retardant, UL 94 V-0 | Choose for electrical connectors, switches and housings needing a V-0 Yellow Card; expect reduced toughness and higher density. | 75 | 8 | ||
MoS2 filled | MoS2 nucleated/lubricated grade with higher crystallinity, slightly better wear, stiffness and dimensional stability than natural. | 78 | 80 | 20 | 83 Shore D |
Heat stabilized | Copper/organic or high-performance stabilizer package for long-term air ageing at 120–150 °C (under-hood, lighting). | 82 | 82 | 35 | 81 Shore D |
40 % mineral filled | Mineral (talc/wollastonite) filler for isotropic shrinkage, flat parts and good paintable surface at modest stiffness gain. | 90 | 4 | ||
15 % short glass fiber reinforced | Moderate stiffness/HDT boost with better surface finish and less warpage than GF30. | 130 | 5 | ||
30 % short glass fiber reinforced | The workhorse structural PA66: high stiffness, ~250 °C HDT and good creep resistance for under-hood and connector parts. | 180 | 3 | 95 HRM | |
20 % carbon fiber reinforced | High specific stiffness with lower density than glass and antistatic behaviour; use where weight and precision matter. | 205 | 2.2 | ||
50 % short glass fiber reinforced | Maximum stiffness and strength for metal-replacement brackets and structural housings; very abrasive and anisotropic. | 230 | 2.3 | ||
30 % carbon fiber reinforced | Stiffest and most dimensionally stable PA66 compound, mildly conductive; chosen for lightweight precision and ESD-sensitive parts. | 240 | 1.8 |
Supply forms, finishes and certifications
Ways PA66 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
EXT | Extruded stock shape | Supply form |
UV | UV / weather stabilized | Grade option |
UnfilledDefault | Natural/unreinforced injection or extrusion grade | Standard supply |
What is PA66?
PA66 is a highly crystalline polyamide condensed from hexamethylenediamine and adipic acid (Zytel, Ultramid A), melting at 260–265 °C and stiffer, more heat-resistant and more wear- and oil-resistant than PA6. Unfilled stock runs 82 MPa tensile, 40 % elongation and 3 GPa modulus; GF30 and GF50 grades raise stiffness and HDT for automotive intake and cooling parts, connectors, gears and bushings. Limits are 8 % saturation moisture uptake that shifts dimensions and strength, weak hydrolysis resistance in hot water and strong acids, and UL94 HB with mediocre UV life unless modified. PA66 has a density of 1.14 g/cm³ (0.0412 lb/in³), lighter than 60% of polymer grades. Its glass-transition temperature is 70°C (158 °F). PA66 has a yield strength of 80 MPa (11.6 ksi) and a tensile strength of 82 MPa (11.9 ksi) — stronger than 88% of polymer grades. Elongation at break is 40% and the elastic modulus is 3 GPa (0.435 Msi).
What is PA66 used for?
- Automotive intake manifolds
- Cooling system housings and fans
- Electrical connectors
- Cable ties
- Gears and bearing bushings
- Fasteners and clips
- Power-tool housings
Advantages
- High strength — 80 MPa (11.6 ksi), better than 88% of polymer grades
Limitations
- Needs corrosion protection — 60/100, worse than 89% of polymer grades
- Absorbs moisture — dry before molding — 1.3%, worse than 88% of polymer grades
- High embodied carbon — 6.7 kg CO₂/kg, worse than 75% of polymer grades
PA66 properties
Typical room-temperature values in the Unfilled condition; bars are the position among polymer grades.
Physical6
PA66 has a density of 1.14 g/cm³ (0.0412 lb/in³), lighter than 60% of polymer grades. Its glass-transition temperature is 70°C (158 °F).
Mechanical17
PA66 has a yield strength of 80 MPa (11.6 ksi) and a tensile strength of 82 MPa (11.9 ksi) — stronger than 88% of polymer grades. Elongation at break is 40% and the elastic modulus is 3 GPa (0.435 Msi).
Thermal11
PA66 is rated for continuous service to 100°C (212 °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 85 µm/m·K (47.2 µin/in·°F).
Electrical7
PA66 is an electrical insulator with a dielectric strength of 22 kV/mm (558.8 V/mil) and a resistivity of 1×10¹² Ω·m.
Chemical & Environmental3
Corrosion resistance is good (60/100), worse than 89% of polymer grades. UV resistance is poor.
Sustainability4
Producing a kilogram of PA66 takes about 120 MJ of energy and emits 6.7 kg of CO₂ — more than 73% of polymer grades. Typical recycled content is 5%.
Manufacturability8
PA66's machinability is good (65/100, better than 66% of polymer grades); weldability very good (70/100); formability fair (50/100).
Common Calculations5
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. PA66 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with PA66
Is PA66 easy to machine?
Machines easily with sharp, positive-rake tools, high speed and low feed; use air or flood coolant to avoid heat build-up and expect stress relief/moisture growth on tight tolerances — glass/carbon filled grades need carbide or PCD.
Can PA66 be welded?
Ultrasonic, hot-plate, spin, vibration and laser welding all work well on dry material; moisture causes porous joints, and glass content above ~30 % lowers weld factor.
Can PA66 be formed, bent or molded?
Dry to <0.15 % moisture, melt 275–300 °C, mold 60–100 °C, fast injection with generous venting; account for 1.0–2.2 % shrink (0.2–0.6 % when glass filled) and anisotropic warpage in fiber-filled parts.
Manufacturability
The process limits FabDigit's quote engine applies to PA66. Design inside these and the part quotes instantly; outside them it routes to an engineer.
CNC machining
| Machinability | Better65 / 100 |
|---|---|
| ISO material group | N.8 |
| Cutting speed (rough / finish) | 360 / 440 m/min |
| Minimum wall | 0.5 mm |
| Minimum internal radius | 1 mm |
| Drill depth limit | 8× diameter |
| Best surface (machined / polished) | Ra 0.8 / 0.4 µm |
| Hardenable after machining | No |
Sheet metal
| Formability | Fair50 / 100 |
|---|---|
| Weldability | Better70 / 100 |
Injection molding
| Mold shrinkage | 1.5 – 2.2 % |
|---|---|
| Wall thickness | 1 – 3.5 mm |
| Recommended draft | 1.5 ° |
| Pre-drying | 80 °C for 4 h |
| UV resistance | Fair |
PA66 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.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| heat/light stabilizers, lubricants, nuclAdditive package varies by grade (Cu/halide, HALS, carbon black, mold release) | 0 – 3 | 0.5 |
| glass fiberOnly in GF15/GF30/GF50 variants (silane-sized E-glass) | 0 – 50 | 0 |
| carbon fiberOnly in CF20/CF30 variants | 0 – 30 | 0 |
| flame retardant systemOnly in FR V-0 variant (brominated + Sb2O3 or halogen-free phosphinate) | 0 – 25 | 0 |
| poly(hexamethylene adipamide) — hexamethBase resin; nominal 1:1 diamine/diacid molar ratio | ≥ 97 (balance) |
What surface finishes work on PA66?
Takes acid dyeing, adhesive bonding (after plasma/primer), painting and vacuum metallizing; direct electroless plating is possible on etched grades, and moisture conditioning is often used to reach in-service dimensions.
Surface treatments FabDigit runs on polymer parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Injection Molding Coating
Organic Coating
Metallization / Functional
Equivalent designations
Standards and trade names that resolve to PA66 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Trade names
- StanylUltramid AVydyneZytelAkulonUltramid
- Also called
- Nylon 66Nylon 101
How much does PA66 cost?
PA66 is a standard-cost polymer ($$), cheaper than about 82% 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.
PA66 — frequently asked
What is PA66 used for?
PA66 is typically used for automotive intake manifolds, cooling system housings and fans, electrical connectors, cable ties, gears and bearing bushings and fasteners and clips. In short: harder wear-resistant nylon.
What is the yield strength of PA66?
PA66 has a typical yield strength of 80 MPa (11.6 ksi) and a tensile strength of 82 MPa (11.9 ksi) — stronger than 88% of polymer grades. Strength varies by condition: see the 12 listed tempers.
Is PA66 easy to machine?
Reasonably — machinability is rated good (65/100, better than 66% of polymer grades). Machines easily with sharp, positive-rake tools, high speed and low feed; use air or flood coolant to avoid heat build-up and expect stress relief/moisture growth on tight tolerances — glass/carbon filled grades need carbide or PCD.
Can PA66 be welded?
Yes — weldability is rated very good (70/100). Ultrasonic, hot-plate, spin, vibration and laser welding all work well on dry material; moisture causes porous joints, and glass content above ~30 % lowers weld factor.
What surface finishes work on PA66?
Takes acid dyeing, adhesive bonding (after plasma/primer), painting and vacuum metallizing; direct electroless plating is possible on etched grades, and moisture conditioning is often used to reach in-service dimensions.
Can PA66 be formed, bent or molded?
Dry to <0.15 % moisture, melt 275–300 °C, mold 60–100 °C, fast injection with generous venting; account for 1.0–2.2 % shrink (0.2–0.6 % when glass filled) and anisotropic warpage in fiber-filled parts.
What is the maximum service temperature of PA66?
PA66 is rated for continuous use to about 100°C (212 °F), and briefly to 170°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does PA66 cost?
PA66 is a standard-cost polymer ($$), cheaper than about 82% 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.
Can FabDigit make parts in PA66?
Yes — PA66 is available for CNC machining, sheet metal and injection molding with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- ISO 16396-1/-2 Plastics — Polyamide (PA) moulding and extrusion materials — ISO (2022)
- ASTM D4066 Standard Classification System for Nylon Injection and Extrusion Materials — ASTM (2019)
- Zytel PA66 product datasheets (101, 70G33, ST801) — DuPont / Celanese (2023)
- Ultramid A (PA66) product range brochure — BASF (2022)
- Ertalon 66 SA stock shape datasheet — Mitsubishi Chemical Advanced Materials (2021)
- Tecamid 66 / Tecamid 66 GF30 datasheets — Ensinger (2022)
- CAMPUS plastics database — PA66 grades — CWFG / CAMPUS consortium (2024)
- Engineering Plastics — Engineered Materials Handbook Vol. 2 — ASM International (1988)
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.