Materials / Compare
Plastic Nylon PA6 vs. Plastic Nylon PA66
Compare Plastic Nylon PA6 vs. Plastic Nylon PA66 strength, stiffness, weight and thermal properties.
| Try it on a partA bracket to run stress or thermal on, free in your browser | Open in LessCAD | Open in LessCAD |
|---|---|---|
| Mechanical | ||
| Yield strength | 90MPasourcetypical, dry | 85MPasourcetypical, dry |
| Ultimate tensile strength | not sourced | not sourced |
| Elongation at break | 10%sourcenominal strain at break, dry | 30%sourcenominal strain at break, dry3x more ductile |
| Young's modulus (stiffness) | 3.5GPasourcetypical, dry17% stiffer | 3GPasourcetypical, dry |
| Density | 1,130kg/m³sourcetypical | 1,130kg/m³sourcetypical |
| Strength to weight | 79.6kN·m/kg6% higher | 75.2kN·m/kg |
| Stiffness to weight | 3.1MN·m/kg17% higher | 2.65MN·m/kg |
| Poisson's ratio | 0.4sourcebase material: unfilled polyamide (PA), conditioned, maker design-guide family value (Covestro Table 3-1) | 0.4sourcebase material: unfilled polyamide (PA), conditioned, maker design-guide family value (Covestro Table 3-1) |
| Shear modulus | 1.25GPa17% stiffer in shear | 1.07GPa |
| Bulk modulus | 5.83GPa | 5GPa |
| Speed of sound | 1,760m/s | 1,629m/s |
| Thermal | ||
| Thermal conductivity | 0.33W/m·Ksourcetypical | 0.33W/m·Ksourcetypical |
| Thermal expansion | 102µm/m·Ksourcelongitudinal, 23-55 °C | 98µm/m·Ksourcelongitudinal, 23-55 °C |
| 100 mm part over a 50 °C swing | 510µm growth | 490µm growth4% less |
| Specific heat | 1,700J/kg·Ksourcetypical | 1,700J/kg·Ksourcetypical |
| Heats up and cools (diffusivity) | 0.172mm²/s | 0.172mm²/s |
| Thermal shock resistance | 49.9W/m | 57.2W/m15% more resistant |
| Melting point | 220°CsourceDSC | 260°CsourceDSC |
| Max service temperature | 87°CsourceIEC 60216 temperature index, 20000 h | 101°CsourceIEC 60216 temperature index, 20000 h16% hotter |
| Values for | BASF Ultramid B3S (PA6, unreinforced injection-moulding grade), Product Information 02/2026, dry values (ISO methods) | BASF Ultramid A3K (PA66, unreinforced injection-moulding grade), Product Information 02/2026, dry values (ISO methods) |
Every value links to the document that states it. "Not sourced" means no citable source states it (or only a specification minimum); figures computed from it are left out too.
Questions
Is Plastic Nylon PA6 stronger than Plastic Nylon PA66?
Plastic Nylon PA6 is stronger: its yield strength is 90 MPa against 85 MPa for Plastic Nylon PA66 (6%).
Which is lighter, Plastic Nylon PA6 or Plastic Nylon PA66?
Plastic Nylon PA6 is lighter: 1,130 kg/m³ against 1,130 kg/m³ for Plastic Nylon PA66.
Which is stiffer, Plastic Nylon PA6 or Plastic Nylon PA66?
Plastic Nylon PA6 is stiffer: Young's modulus 3.5 GPa against 3 GPa for Plastic Nylon PA66, so the same part in Plastic Nylon PA6 deflects less under the same load.
Which is lighter for the same job, Plastic Nylon PA6 or Plastic Nylon PA66?
For the same stiffness or strength: Plastic Nylon PA6 is lighter for a stiff rod or tie (tension), stiff beam (bending), stiff panel or plate, strong rod or tie, strong beam, strong panel or plate.
| Part that must be | Plastic Nylon PA6 | Plastic Nylon PA66 |
|---|---|---|
| Stiff rod or tie (tension) | lighter | 17% heavier |
| Stiff beam (bending) | lighter | 8% heavier |
| Stiff panel or plate | lighter | 5% heavier |
| Strong rod or tie | lighter | 6% heavier |
| Strong beam | lighter | 4% heavier |
| Strong panel or plate | lighter | 3% heavier |
For the same stiffness or strength, mass scales with density over stiffness (or strength) raised to a power set by how the part is loaded: 1 for a rod in tension, 1/2 for a beam in bending, 1/3 for a panel (the standard material-selection indices).
Which is more ductile, Plastic Nylon PA6 or Plastic Nylon PA66?
Plastic Nylon PA66 stretches further before it breaks: 30% elongation at break against 10% for Plastic Nylon PA6.
Which handles higher temperatures, Plastic Nylon PA6 or Plastic Nylon PA66?
Plastic Nylon PA66 does: 101 °C against 87 °C for Plastic Nylon PA6, both IEC 60216 temperature index, 20000 h.
Which conducts heat better, Plastic Nylon PA6 or Plastic Nylon PA66?
Plastic Nylon PA6 conducts heat better: 0.33 W/m·K against 0.33 W/m·K for Plastic Nylon PA66.
Which expands less with temperature?
Plastic Nylon PA66 expands less: 98 µm/m·K against 102 µm/m·K for Plastic Nylon PA6.