Materials / Compare
Plastic Nylon PA6 vs. Stainless 303
Compare Plastic Nylon PA6 vs. Stainless 303 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 | 275MPasourceOutokumpu typical (product P = hot rolled plate, transverse) |
| Ultimate tensile strength | not sourced | 585MPasourceOutokumpu typical |
| Elongation at break | 10%sourcenominal strain at break, dry | 35%sourceOutokumpu typical, A5 |
| Young's modulus (stiffness) | 3.5GPasourcetypical, dry | 200GPasourceat RT (Table 12) |
| Density | 1,130kg/m³sourcetypical | 7,900kg/m³sourceat RT |
| Strength to weight | 79.6kN·m/kg2.29x higher | 34.8kN·m/kg |
| Stiffness to weight | 3.1MN·m/kg | 25.3MN·m/kg8.17x 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 | 1.25GPa | 76.9GPa61.5x stiffer in shear |
| Bulk modulus | 5.83GPa | 167GPa |
| Speed of sound | 1,760m/s | 5,032m/s |
| Thermal | ||
| Thermal conductivity | 0.33W/m·Ksourcetypical | 15W/m·Ksourceat RT |
| Thermal expansion | 102µm/m·Ksourcelongitudinal, 23-55 °C | 16µm/m·Ksourcemean, 20–100 °C |
| 100 mm part over a 50 °C swing | 510µm growth | 80µm growth6.38x less |
| Specific heat | 1,700J/kg·Ksourcetypical | 500J/kg·Ksourceat RT |
| Heats up and cools (diffusivity) | 0.172mm²/s | 3.8mm²/s22.1x faster |
| Thermal shock resistance | 49.9W/m | 902W/m18.1x more resistant |
| Melting point | 220°CsourceDSC | not sourced |
| Max service temperature | 87°CsourceIEC 60216 temperature index, 20000 h | 871°Csourcecontinuous, scaling limit |
| Values for | BASF Ultramid B3S (PA6, unreinforced injection-moulding grade), Product Information 02/2026, dry values (ISO methods) | 1.4305 / UNS S30300, Outokumpu typical values (hot rolled, solution annealed) from 'Steel Grades, Properties and Global Standards'; max service from Carpenter CarTech 303 datasheet |
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 Stainless 303?
Stainless 303 is stronger: its yield strength is 275 MPa against 90 MPa for Plastic Nylon PA6 (3.06x).
Which is lighter, Plastic Nylon PA6 or Stainless 303?
Plastic Nylon PA6 is lighter: 1,130 kg/m³ against 7,900 kg/m³ for Stainless 303.
Which is stiffer, Plastic Nylon PA6 or Stainless 303?
Stainless 303 is stiffer: Young's modulus 200 GPa against 3.5 GPa for Plastic Nylon PA6, so the same part in Stainless 303 deflects less under the same load.
Which is lighter for the same job, Plastic Nylon PA6 or Stainless 303?
For the same stiffness or strength: Plastic Nylon PA6 is lighter for a stiff panel or plate, strong rod or tie, strong beam, strong panel or plate; Stainless 303 is lighter for a stiff rod or tie (tension), stiff beam (bending).
| Part that must be | Plastic Nylon PA6 | Stainless 303 |
|---|---|---|
| Stiff rod or tie (tension) | 8.17x heavier | lighter |
| Stiff beam (bending) | 8% heavier | lighter |
| Stiff panel or plate | lighter | 1.82x heavier |
| Strong rod or tie | lighter | 2.29x heavier |
| Strong beam | lighter | 3.32x heavier |
| Strong panel or plate | lighter | 4x 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 PA6 or Stainless 303?
Stainless 303 conducts heat better: 15 W/m·K against 0.33 W/m·K for Plastic Nylon PA6.
Which expands less with temperature?
Stainless 303 expands less: 16 µm/m·K against 102 µm/m·K for Plastic Nylon PA6.