Materials / Compare
Plastic PTFE vs. Stainless 303
Compare Plastic PTFE 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 | 9MPasourcetypical yield strength at 23 °C (Teflon PTFE, Table 8) | 275MPasourceOutokumpu typical (product P = hot rolled plate, transverse) |
| Ultimate tensile strength | 39.3MPasourcetypical, skived tape 0.13 mm | 585MPasourceOutokumpu typical |
| Elongation at break | 350%sourcetypical, skived tape 0.13 mm | 35%sourceOutokumpu typical, A5 |
| Young's modulus (stiffness) | not sourced | 200GPasourceat RT (Table 12) |
| Density | 2,160kg/m³sourcetypical (standard specific gravity, ASTM D4894) | 7,900kg/m³sourceat RT |
| Strength to weight | 4.17kN·m/kg | 34.8kN·m/kg8.35x higher |
| Stiffness to weight | not sourced | 25.3MN·m/kg |
| Poisson's ratio | 0.46sourcetypical, 23 °C (Teflon PTFE resins, Chemours handbook) | 0.3sourcedesign value (structural stainless steels) |
| Shear modulus | not sourced | 76.9GPa |
| Bulk modulus | not sourced | 167GPa |
| Speed of sound | not sourced | 5,032m/s |
| Thermal | ||
| Thermal conductivity | 0.25W/m·Ksourcetypical, granular resin, 4.6 mm specimen | 15W/m·Ksourceat RT |
| Thermal expansion | 100µm/m·Ksourcetypical, granular resin, 23-60 °C (ASTM E228) | 16µm/m·Ksourcemean, 20–100 °C |
| 100 mm part over a 50 °C swing | 500µm growth | 80µm growth6.25x less |
| Specific heat | 1,400J/kg·Ksourcetypical, granular resin, 20 °C (ASTM D4591) | 500J/kg·Ksourceat RT |
| Heats up and cools (diffusivity) | 0.0827mm²/s | 3.8mm²/s45.9x faster |
| Thermal shock resistance | not sourced | 902W/m |
| Melting point | 327°Csourcesecond melting peak (sintered polymer), +/-10 | not sourced |
| Max service temperature | 260°Csourceservice temperature (Chemours general Teflon PTFE statement) | 871°Csourcecontinuous, scaling limit |
| Values for | Chemours Teflon PTFE 7C X granular molding resin, typical values (tensile/elongation measured on 0.13 mm skived tape) | 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 PTFE stronger than Stainless 303?
Stainless 303 is stronger: its yield strength is 275 MPa against 9 MPa for Plastic PTFE (30.6x).
Which is lighter, Plastic PTFE or Stainless 303?
Plastic PTFE is lighter: 2,160 kg/m³ against 7,900 kg/m³ for Stainless 303.
Which is lighter for the same job, Plastic PTFE or Stainless 303?
For the same stiffness or strength: Stainless 303 is lighter for a strong rod or tie, strong beam, strong panel or plate.
| Part that must be | Plastic PTFE | Stainless 303 |
|---|---|---|
| Strong rod or tie | 8.35x heavier | lighter |
| Strong beam | 2.67x heavier | lighter |
| Strong panel or plate | 1.51x 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 303?
Stainless 303 conducts heat better: 15 W/m·K against 0.25 W/m·K for Plastic PTFE.
Which expands less with temperature?
Stainless 303 expands less: 16 µm/m·K against 100 µm/m·K for Plastic PTFE.