Materials / Compare
Stainless 304 vs. Plastic UHMWPE
Compare Stainless 304 vs. Plastic UHMWPE 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 | 241MPasourcetypical, annealed, 70 °F (21 °C) | 20MPasourcetypical, tensile stress at yield ISO 527, 50 mm/min |
| Ultimate tensile strength | 586MPasourcetypical, annealed, 70 °F (21 °C) | 43MPasourcetypical, tensile stress at break ISO 527, 50 mm/min |
| Elongation at break | 55%sourcetypical, annealed, in 2 in. (50.8 mm) | 465%sourcetypical, nominal elongation at break ISO 527 |
| Young's modulus (stiffness) | 193GPasourcetypical, in tension | 0.66GPasourcetypical, tensile modulus ISO 527, 1 mm/min |
| Density | 8,030kg/m³sourcetypical | 930kg/m³sourcetypical8.63x lighter |
| Strength to weight | 30kN·m/kg40% higher | 21.5kN·m/kg |
| Stiffness to weight | 24MN·m/kg33.9x higher | 0.71MN·m/kg |
| Poisson's ratio | 0.3sourcedesign value (structural stainless steels) | not sourced |
| Shear modulus | 74.2GPa | not sourced |
| Bulk modulus | 161GPa | not sourced |
| Speed of sound | 4,903m/s | 842m/s |
| Thermal | ||
| Thermal conductivity | 16.2W/m·Ksourceat 100 °C | 0.4W/m·Ksourcetypical, unfilled (narrative value, generic Celanese UHMWPE) |
| Thermal expansion | 16.9µm/m·Ksourcemean, 0–100 °C | 200µm/m·Ksourcetypical, 20 to 100 °C (generic Celanese UHMWPE) |
| 100 mm part over a 50 °C swing | 84.5µm growth11.8x less | 1,000µm growth |
| Specific heat | 500J/kg·Ksourcemean, 0–100 °C | not sourced |
| Heats up and cools (diffusivity) | 4.03mm²/s | not sourced |
| Thermal shock resistance | 838W/m | not sourced |
| Melting point | 1,399–1,454°Csourcemelting range | 130–138°CsourceDSC 10 K/min |
| Max service temperature | 899°Csourcecontinuous, oxidation (scaling) limit in air | 80°Csourcerecommended max constant operating temperature |
| Values for | 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 | Celanese GUR 4120 (avg. molecular weight 4.7x10^6 g/mol), typical values on compression-molded specimens; CTE and thermal conductivity from Celanese's generic UHMWPE guide (grade not named) |
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 Stainless 304 stronger than Plastic UHMWPE?
Stainless 304 is stronger: its yield strength is 241 MPa against 20 MPa for Plastic UHMWPE (12.1x).
Which is lighter, Stainless 304 or Plastic UHMWPE?
Plastic UHMWPE is lighter: 930 kg/m³ against 8,030 kg/m³ for Stainless 304.
Which is stiffer, Stainless 304 or Plastic UHMWPE?
Stainless 304 is stiffer: Young's modulus 193 GPa against 0.66 GPa for Plastic UHMWPE, so the same part in Stainless 304 deflects less under the same load.
Which is lighter for the same job, Stainless 304 or Plastic UHMWPE?
For the same stiffness or strength: Stainless 304 is lighter for a stiff rod or tie (tension), stiff beam (bending), strong rod or tie; Plastic UHMWPE is lighter for a stiff panel or plate, strong beam, strong panel or plate.
| Part that must be | Stainless 304 | Plastic UHMWPE |
|---|---|---|
| Stiff rod or tie (tension) | lighter | 33.9x heavier |
| Stiff beam (bending) | lighter | 1.98x heavier |
| Stiff panel or plate | 30% heavier | lighter |
| Strong rod or tie | lighter | 40% heavier |
| Strong beam | 1.64x heavier | lighter |
| Strong panel or plate | 2.49x 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, Stainless 304 or Plastic UHMWPE?
Stainless 304 conducts heat better: 16.2 W/m·K against 0.4 W/m·K for Plastic UHMWPE.
Which expands less with temperature?
Stainless 304 expands less: 16.9 µm/m·K against 200 µm/m·K for Plastic UHMWPE.