Materials / Compare
Iron vs. Plastic PTFE
Compare Iron vs. Plastic PTFE 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 | 9MPasourcetypical yield strength at 23 °C (Teflon PTFE, Table 8) |
| Ultimate tensile strength | 290MPasourcetypical, SRA/recrystallization anneal | 39.3MPasourcetypical, skived tape 0.13 mm |
| Elongation at break | 38%sourcetypical, gauge 4D0 | 350%sourcetypical, skived tape 0.13 mm |
| Young's modulus (stiffness) | 207GPasourcetypical, after SRA/recrystallization anneal | not sourced |
| Density | 7,860kg/m³sourcetypical | 2,160kg/m³sourcetypical (standard specific gravity, ASTM D4894) |
| Strength to weight | 23.7kN·m/kg5.68x higher | 4.17kN·m/kg |
| Stiffness to weight | 26.3MN·m/kg | not sourced |
| Poisson's ratio | 0.282sourceNIST critically evaluated best value (polycrystalline iron) | 0.46sourcetypical, 23 °C (Teflon PTFE resins, Chemours handbook) |
| Shear modulus | 80.7GPa | not sourced |
| Bulk modulus | 158GPa | not sourced |
| Speed of sound | 5,132m/s | not sourced |
| Thermal | ||
| Thermal conductivity | 73.2W/m·Ksourcetypical at 20 °C | 0.25W/m·Ksourcetypical, granular resin, 4.6 mm specimen |
| Thermal expansion | 13.7µm/m·Ksourcemean, 20-399 °C | 100µm/m·Ksourcetypical, granular resin, 23-60 °C (ASTM E228) |
| 100 mm part over a 50 °C swing | 68.5µm growth7.3x less | 500µm growth |
| Specific heat | 450J/kg·Ksourcetypical | 1,400J/kg·Ksourcetypical, granular resin, 20 °C (ASTM D4591) |
| Heats up and cools (diffusivity) | 20.7mm²/s250x faster | 0.0827mm²/s |
| Thermal shock resistance | 3,447W/m | not sourced |
| Melting point | 1,532°Csourcetypical | 327°Csourcesecond melting peak (sintered polymer), +/-10 |
| Max service temperature | not sourced | 260°Csourceservice temperature (Chemours general Teflon PTFE statement) |
| 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. | Chemours Teflon PTFE 7C X granular molding resin, typical values (tensile/elongation measured on 0.13 mm skived tape) |
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 PTFE?
Iron is stronger: its yield strength is 186 MPa against 9 MPa for Plastic PTFE (20.7x).
Which is lighter, Iron or Plastic PTFE?
Plastic PTFE is lighter: 2,160 kg/m³ against 7,860 kg/m³ for Iron.
Which is lighter for the same job, Iron or Plastic PTFE?
For the same stiffness or strength: Iron is lighter for a strong rod or tie, strong beam, strong panel or plate.
| Part that must be | Iron | Plastic PTFE |
|---|---|---|
| Strong rod or tie | lighter | 5.68x heavier |
| Strong beam | lighter | 2.07x heavier |
| Strong panel or plate | lighter | 25% 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, Iron or Plastic PTFE?
Iron conducts heat better: 73.2 W/m·K against 0.25 W/m·K for Plastic PTFE.
Which expands less with temperature?
Iron expands less: 13.7 µm/m·K against 100 µm/m·K for Plastic PTFE.