Materials / Compare
Plastic Nylon PA66 vs. Plastic PETG
Compare Plastic Nylon PA66 vs. Plastic PETG 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 | 85MPasourcetypical, dry | 46.2MPasourcetypical |
| Ultimate tensile strength | not sourced | 46.2MPasourcetypical, peak stress (= stress at yield) |
| Flexural strength | not sourced | 78.9MPasourcetypical |
| Elongation at break | 30%sourcenominal strain at break, dry | 7.6%sourcetypical |
| Young's modulus (stiffness) | 3GPasourcetypical, dry | 1.94GPasourcetypical |
| Density | 1,130kg/m³sourcetypical12% lighter | 1,270kg/m³sourcetypical |
| Strength to weight | 75.2kN·m/kg2.07x higher | 36.4kN·m/kg |
| Stiffness to weight | 2.65MN·m/kg1.74x higher | 1.53MN·m/kg |
| Poisson's ratio | 0.4sourcebase material: unfilled polyamide (PA), conditioned, maker design-guide family value (Covestro Table 3-1) | not sourced |
| Shear modulus | 1.07GPa | not sourced |
| Bulk modulus | 5GPa | not sourced |
| Speed of sound | 1,629m/s | 1,236m/s |
| Thermal | ||
| Thermal conductivity | 0.33W/m·Ksourcetypical | 0.21W/m·Ksourcebase material: Eastman Eastar Copolyester 6763 (PETG), typical |
| Thermal expansion | 98µm/m·Ksourcelongitudinal, 23-55 °C | 51µm/m·Ksourcebase material: Eastman Eastar Copolyester 6763 (PETG), typical |
| 100 mm part over a 50 °C swing | 490µm growth | 255µm growth1.92x less |
| Specific heat | 1,700J/kg·Ksourcetypical | 1,300J/kg·Ksourcebase material: Eastman Eastar Copolyester 6763 (PETG), DSC at 60 °C (lowest temperature listed) |
| Heats up and cools (diffusivity) | 0.172mm²/s35% faster | 0.127mm²/s |
| Thermal shock resistance | 57.2W/m | not sourced |
| Melting point | 260°CsourceDSC | not sourced |
| Glass transition | not sourced | 77.4°Csourcetypical |
| Max service temperature | 101°CsourceIEC 60216 temperature index, 20000 h | 76.2°CsourceHDT 0.455 MPa (printed specimens) |
| Values for | BASF Ultramid A3K (PA66, unreinforced injection-moulding grade), Product Information 02/2026, dry values (ISO methods) | Ultimaker PETG, 3D-printed specimens, XY (flat); Ultimaker S5 Pro, engineering intent profile, 0.15 mm layer height, AA 0.4 print core, 100% infill, Cura 4.9, printed one-at-a-time, conditioned >=24 h at room temperature. TDS v1.00, April 29, 2022. |
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.
Plastic PETG is 3D printed: its properties depend on build direction and print settings; these are typical values.
Questions
Is Plastic Nylon PA66 stronger than Plastic PETG?
Plastic Nylon PA66 is stronger: its yield strength is 85 MPa against 46.2 MPa for Plastic PETG (1.84x).
Which is lighter, Plastic Nylon PA66 or Plastic PETG?
Plastic Nylon PA66 is lighter: 1,130 kg/m³ against 1,270 kg/m³ for Plastic PETG.
Which is stiffer, Plastic Nylon PA66 or Plastic PETG?
Plastic Nylon PA66 is stiffer: Young's modulus 3 GPa against 1.94 GPa for Plastic PETG, so the same part in Plastic Nylon PA66 deflects less under the same load.
Which is lighter for the same job, Plastic Nylon PA66 or Plastic PETG?
For the same stiffness or strength: Plastic Nylon PA66 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 PA66 | Plastic PETG |
|---|---|---|
| Stiff rod or tie (tension) | lighter | 1.74x heavier |
| Stiff beam (bending) | lighter | 40% heavier |
| Stiff panel or plate | lighter | 30% heavier |
| Strong rod or tie | lighter | 2.07x heavier |
| Strong beam | lighter | 1.69x heavier |
| Strong panel or plate | lighter | 1.52x 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 conducts heat better, Plastic Nylon PA66 or Plastic PETG?
Plastic Nylon PA66 conducts heat better: 0.33 W/m·K against 0.21 W/m·K for Plastic PETG.
Which expands less with temperature?
Plastic PETG expands less: 51 µm/m·K against 98 µm/m·K for Plastic Nylon PA66.