Materials / Compare
Plastic Nylon PA66 vs. Stainless 304
Compare Plastic Nylon PA66 vs. Stainless 304 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 | 241MPasourcetypical, annealed, 70 °F (21 °C) |
| Ultimate tensile strength | not sourced | 586MPasourcetypical, annealed, 70 °F (21 °C) |
| Elongation at break | 30%sourcenominal strain at break, dry | 55%sourcetypical, annealed, in 2 in. (50.8 mm) |
| Young's modulus (stiffness) | 3GPasourcetypical, dry | 193GPasourcetypical, in tension |
| Density | 1,130kg/m³sourcetypical7.11x lighter | 8,030kg/m³sourcetypical |
| Strength to weight | 75.2kN·m/kg2.51x higher | 30kN·m/kg |
| Stiffness to weight | 2.65MN·m/kg | 24MN·m/kg9.05x higher |
| Poisson's ratio | 0.4sourcebase material: unfilled polyamide (PA), conditioned, maker design-guide family value (Covestro Table 3-1) | 0.3sourcedesign value (structural stainless steels) |
| Shear modulus | 1.07GPa | 74.2GPa69.3x stiffer in shear |
| Bulk modulus | 5GPa | 161GPa |
| Speed of sound | 1,629m/s | 4,903m/s |
| Thermal | ||
| Thermal conductivity | 0.33W/m·Ksourcetypical | 16.2W/m·Ksourceat 100 °C |
| Thermal expansion | 98µm/m·Ksourcelongitudinal, 23-55 °C | 16.9µm/m·Ksourcemean, 0–100 °C |
| 100 mm part over a 50 °C swing | 490µm growth | 84.5µm growth5.8x less |
| Specific heat | 1,700J/kg·Ksourcetypical | 500J/kg·Ksourcemean, 0–100 °C |
| Heats up and cools (diffusivity) | 0.172mm²/s | 4.03mm²/s23.5x faster |
| Thermal shock resistance | 57.2W/m | 838W/m14.6x more resistant |
| Melting point | 260°CsourceDSC | 1,399–1,454°Csourcemelting range |
| Max service temperature | 101°CsourceIEC 60216 temperature index, 20000 h | 899°Csourcecontinuous, oxidation (scaling) limit in air |
| Values for | BASF Ultramid A3K (PA66, unreinforced injection-moulding grade), Product Information 02/2026, dry values (ISO methods) | Type 304, annealed flat-rolled (Cleveland-Cliffs 304/304L Product Data Bulletin, May 2021); Poisson's ratio from the Nickel Institute/SCI structural stainless design manual |
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 PA66 stronger than Stainless 304?
Stainless 304 is stronger: its yield strength is 241 MPa against 85 MPa for Plastic Nylon PA66 (2.84x).
Which is lighter, Plastic Nylon PA66 or Stainless 304?
Plastic Nylon PA66 is lighter: 1,130 kg/m³ against 8,030 kg/m³ for Stainless 304.
Which is stiffer, Plastic Nylon PA66 or Stainless 304?
Stainless 304 is stiffer: Young's modulus 193 GPa against 3 GPa for Plastic Nylon PA66, so the same part in Stainless 304 deflects less under the same load.
Which is lighter for the same job, Plastic Nylon PA66 or Stainless 304?
For the same stiffness or strength: Plastic Nylon PA66 is lighter for a stiff panel or plate, strong rod or tie, strong beam, strong panel or plate; Stainless 304 is lighter for a stiff rod or tie (tension), stiff beam (bending).
| Part that must be | Plastic Nylon PA66 | Stainless 304 |
|---|---|---|
| Stiff rod or tie (tension) | 9.05x heavier | lighter |
| Stiff beam (bending) | 13% heavier | lighter |
| Stiff panel or plate | lighter | 1.77x heavier |
| Strong rod or tie | lighter | 2.51x heavier |
| Strong beam | lighter | 3.55x heavier |
| Strong panel or plate | lighter | 4.22x 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 Stainless 304?
Stainless 304 conducts heat better: 16.2 W/m·K against 0.33 W/m·K for Plastic Nylon PA66.
Which expands less with temperature?
Stainless 304 expands less: 16.9 µm/m·K against 98 µm/m·K for Plastic Nylon PA66.