Materials / Compare
Iron vs. Plastic Polycarbonate
Compare Iron vs. Plastic Polycarbonate 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 | 65MPasourcetypical, tensile yield |
| Ultimate tensile strength | 290MPasourcetypical, SRA/recrystallization anneal | 65MPasourcetypical, stress at break |
| Flexural strength | not sourced | 97MPasourcetypical, flexural strength |
| Elongation at break | 38%sourcetypical, gauge 4D0 | 125%sourcetypical, strain at break |
| Young's modulus (stiffness) | 207GPasourcetypical, after SRA/recrystallization anneal | 2.4GPasourcetypical |
| Density | 7,860kg/m³sourcetypical | 1,200kg/m³sourcetypical6.55x lighter |
| Strength to weight | 23.7kN·m/kg | 54.2kN·m/kg2.29x higher |
| Stiffness to weight | 26.3MN·m/kg13.2x higher | 2MN·m/kg |
| Poisson's ratio | 0.282sourceNIST critically evaluated best value (polycrystalline iron) | 0.38sourcetypical, polycarbonate family (Covestro Part and Mold Design guide, Table 3-1) |
| Shear modulus | 80.7GPa92.8x stiffer in shear | 0.87GPa |
| Bulk modulus | 158GPa | 3.33GPa |
| Speed of sound | 5,132m/s | 1,414m/s |
| Thermal | ||
| Thermal conductivity | 73.2W/m·Ksourcetypical at 20 °C | 0.2W/m·Ksourcetypical, through-plane, 23 C |
| Thermal expansion | 13.7µm/m·Ksourcemean, 20-399 °C | 65µm/m·Ksourcetypical, 23-55 C, parallel and normal |
| 100 mm part over a 50 °C swing | 68.5µm growth4.74x less | 325µm growth |
| Specific heat | 450J/kg·Ksourcetypical | 1,172J/kg·Ksourcetypical (guide value), Bayer ASTM datasheet for Makrolon 2405, ASTM D 2766 |
| Heats up and cools (diffusivity) | 20.7mm²/s146x faster | 0.142mm²/s |
| Thermal shock resistance | 3,447W/m66.7x more resistant | 51.7W/m |
| Melting point | 1,532°Csourcetypical | not sourced |
| Glass transition | not sourced | 144°Csourcetypical, DSC 10 C/min |
| Max service temperature | not sourced | 125°CsourceUL 746B RTI, tensile strength, 1.5 mm |
| 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. | Covestro Makrolon 2405 general-purpose PC (MVR 19), Covestro technical datasheet version 2026-09-28, typical values |
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 Polycarbonate?
Iron is stronger: its yield strength is 186 MPa against 65 MPa for Plastic Polycarbonate (2.86x).
Which is lighter, Iron or Plastic Polycarbonate?
Plastic Polycarbonate is lighter: 1,200 kg/m³ against 7,860 kg/m³ for Iron.
Which is stiffer, Iron or Plastic Polycarbonate?
Iron is stiffer: Young's modulus 207 GPa against 2.4 GPa for Plastic Polycarbonate, so the same part in Iron deflects less under the same load.
Which is lighter for the same job, Iron or Plastic Polycarbonate?
For the same stiffness or strength: Iron is lighter for a stiff rod or tie (tension), stiff beam (bending); Plastic Polycarbonate is lighter for a stiff panel or plate, strong rod or tie, strong beam, strong panel or plate.
| Part that must be | Iron | Plastic Polycarbonate |
|---|---|---|
| Stiff rod or tie (tension) | lighter | 13.2x heavier |
| Stiff beam (bending) | lighter | 42% heavier |
| Stiff panel or plate | 48% heavier | lighter |
| Strong rod or tie | 2.29x heavier | lighter |
| Strong beam | 3.25x heavier | lighter |
| Strong panel or plate | 3.87x 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 Polycarbonate?
Iron conducts heat better: 73.2 W/m·K against 0.2 W/m·K for Plastic Polycarbonate.
Which expands less with temperature?
Iron expands less: 13.7 µm/m·K against 65 µm/m·K for Plastic Polycarbonate.