Materials / Compare
Iron vs. Plastic Nylon PA66
Compare Iron 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 | 186MPasourcetypical (0.2% YS), hot rolled + SRA/recrystallization anneal | 85MPasourcetypical, dry |
| Ultimate tensile strength | 290MPasourcetypical, SRA/recrystallization anneal | not sourced |
| Elongation at break | 38%sourcetypical, gauge 4D0 | 30%sourcenominal strain at break, dry |
| Young's modulus (stiffness) | 207GPasourcetypical, after SRA/recrystallization anneal | 3GPasourcetypical, dry |
| Density | 7,860kg/m³sourcetypical | 1,130kg/m³sourcetypical6.96x lighter |
| Strength to weight | 23.7kN·m/kg | 75.2kN·m/kg3.18x higher |
| Stiffness to weight | 26.3MN·m/kg9.92x higher | 2.65MN·m/kg |
| Poisson's ratio | 0.282sourceNIST critically evaluated best value (polycrystalline iron) | 0.4sourcebase material: unfilled polyamide (PA), conditioned, maker design-guide family value (Covestro Table 3-1) |
| Shear modulus | 80.7GPa75.4x stiffer in shear | 1.07GPa |
| Bulk modulus | 158GPa | 5GPa |
| Speed of sound | 5,132m/s | 1,629m/s |
| Thermal | ||
| Thermal conductivity | 73.2W/m·Ksourcetypical at 20 °C | 0.33W/m·Ksourcetypical |
| Thermal expansion | 13.7µm/m·Ksourcemean, 20-399 °C | 98µm/m·Ksourcelongitudinal, 23-55 °C |
| 100 mm part over a 50 °C swing | 68.5µm growth7.15x less | 490µm growth |
| Specific heat | 450J/kg·Ksourcetypical | 1,700J/kg·Ksourcetypical |
| Heats up and cools (diffusivity) | 20.7mm²/s120x faster | 0.172mm²/s |
| Thermal shock resistance | 3,447W/m60.2x more resistant | 57.2W/m |
| Melting point | 1,532°Csourcetypical | 260°CsourceDSC |
| Max service temperature | not sourced | 101°CsourceIEC 60216 temperature index, 20000 h |
| Values for | Cleveland-Cliffs / AK Steel ARMCO Pure Iron Product Data Bulletin (07/2022): Table 1 typical physical properties, Table 2 typical mechanical properties after SRA/recrystallization anneal. | 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 Iron stronger than Plastic Nylon PA66?
Iron is stronger: its yield strength is 186 MPa against 85 MPa for Plastic Nylon PA66 (2.19x).
Which is lighter, Iron or Plastic Nylon PA66?
Plastic Nylon PA66 is lighter: 1,130 kg/m³ against 7,860 kg/m³ for Iron.
Which is stiffer, Iron or Plastic Nylon PA66?
Iron is stiffer: Young's modulus 207 GPa against 3 GPa for Plastic Nylon PA66, so the same part in Iron deflects less under the same load.
Which is lighter for the same job, Iron or Plastic Nylon PA66?
For the same stiffness or strength: Iron is lighter for a stiff rod or tie (tension), stiff beam (bending); Plastic Nylon PA66 is lighter for a stiff panel or plate, strong rod or tie, strong beam, strong panel or plate.
| Part that must be | Iron | Plastic Nylon PA66 |
|---|---|---|
| Stiff rod or tie (tension) | lighter | 9.92x heavier |
| Stiff beam (bending) | lighter | 19% heavier |
| Stiff panel or plate | 1.7x heavier | lighter |
| Strong rod or tie | 3.18x heavier | lighter |
| Strong beam | 4.13x heavier | lighter |
| Strong panel or plate | 4.7x heavier | lighter |
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, Iron or Plastic Nylon PA66?
Iron conducts heat better: 73.2 W/m·K against 0.33 W/m·K for Plastic Nylon PA66.
Which expands less with temperature?
Iron expands less: 13.7 µm/m·K against 98 µm/m·K for Plastic Nylon PA66.