Materials / Compare
Plastic PTFE vs. Stainless 304
Compare Plastic PTFE 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 | 9MPasourcetypical yield strength at 23 °C (Teflon PTFE, Table 8) | 241MPasourcetypical, annealed, 70 °F (21 °C) |
| Ultimate tensile strength | 39.3MPasourcetypical, skived tape 0.13 mm | 586MPasourcetypical, annealed, 70 °F (21 °C) |
| Elongation at break | 350%sourcetypical, skived tape 0.13 mm | 55%sourcetypical, annealed, in 2 in. (50.8 mm) |
| Young's modulus (stiffness) | not sourced | 193GPasourcetypical, in tension |
| Density | 2,160kg/m³sourcetypical (standard specific gravity, ASTM D4894) | 8,030kg/m³sourcetypical |
| Strength to weight | 4.17kN·m/kg | 30kN·m/kg7.2x higher |
| Stiffness to weight | not sourced | 24MN·m/kg |
| Poisson's ratio | 0.46sourcetypical, 23 °C (Teflon PTFE resins, Chemours handbook) | 0.3sourcedesign value (structural stainless steels) |
| Shear modulus | not sourced | 74.2GPa |
| Bulk modulus | not sourced | 161GPa |
| Speed of sound | not sourced | 4,903m/s |
| Thermal | ||
| Thermal conductivity | 0.25W/m·Ksourcetypical, granular resin, 4.6 mm specimen | 16.2W/m·Ksourceat 100 °C |
| Thermal expansion | 100µm/m·Ksourcetypical, granular resin, 23-60 °C (ASTM E228) | 16.9µm/m·Ksourcemean, 0–100 °C |
| 100 mm part over a 50 °C swing | 500µm growth | 84.5µm growth5.92x less |
| Specific heat | 1,400J/kg·Ksourcetypical, granular resin, 20 °C (ASTM D4591) | 500J/kg·Ksourcemean, 0–100 °C |
| Heats up and cools (diffusivity) | 0.0827mm²/s | 4.03mm²/s48.8x faster |
| Thermal shock resistance | not sourced | 838W/m |
| Melting point | 327°Csourcesecond melting peak (sintered polymer), +/-10 | 1,399–1,454°Csourcemelting range |
| Max service temperature | 260°Csourceservice temperature (Chemours general Teflon PTFE statement) | 899°Csourcecontinuous, oxidation (scaling) limit in air |
| Values for | Chemours Teflon PTFE 7C X granular molding resin, typical values (tensile/elongation measured on 0.13 mm skived tape) | 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 PTFE stronger than Stainless 304?
Stainless 304 is stronger: its yield strength is 241 MPa against 9 MPa for Plastic PTFE (26.8x).
Which is lighter, Plastic PTFE or Stainless 304?
Plastic PTFE is lighter: 2,160 kg/m³ against 8,030 kg/m³ for Stainless 304.
Which is lighter for the same job, Plastic PTFE or Stainless 304?
For the same stiffness or strength: Stainless 304 is lighter for a strong rod or tie, strong beam, strong panel or plate.
| Part that must be | Plastic PTFE | Stainless 304 |
|---|---|---|
| Strong rod or tie | 7.2x heavier | lighter |
| Strong beam | 2.41x heavier | lighter |
| Strong panel or plate | 39% 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, Plastic PTFE or Stainless 304?
Stainless 304 conducts heat better: 16.2 W/m·K against 0.25 W/m·K for Plastic PTFE.
Which expands less with temperature?
Stainless 304 expands less: 16.9 µm/m·K against 100 µm/m·K for Plastic PTFE.