Materials / Compare
Stainless 303 vs. Plastic UHMWPE
Compare Stainless 303 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 | 275MPasourceOutokumpu typical (product P = hot rolled plate, transverse) | 20MPasourcetypical, tensile stress at yield ISO 527, 50 mm/min |
| Ultimate tensile strength | 585MPasourceOutokumpu typical | 43MPasourcetypical, tensile stress at break ISO 527, 50 mm/min |
| Elongation at break | 35%sourceOutokumpu typical, A5 | 465%sourcetypical, nominal elongation at break ISO 527 |
| Young's modulus (stiffness) | 200GPasourceat RT (Table 12) | 0.66GPasourcetypical, tensile modulus ISO 527, 1 mm/min |
| Density | 7,900kg/m³sourceat RT | 930kg/m³sourcetypical |
| Strength to weight | 34.8kN·m/kg1.62x higher | 21.5kN·m/kg |
| Stiffness to weight | 25.3MN·m/kg35.7x higher | 0.71MN·m/kg |
| Poisson's ratio | 0.3sourcedesign value (structural stainless steels) | not sourced |
| Shear modulus | 76.9GPa | not sourced |
| Bulk modulus | 167GPa | not sourced |
| Speed of sound | 5,032m/s | 842m/s |
| Thermal | ||
| Thermal conductivity | 15W/m·Ksourceat RT | 0.4W/m·Ksourcetypical, unfilled (narrative value, generic Celanese UHMWPE) |
| Thermal expansion | 16µm/m·Ksourcemean, 20–100 °C | 200µm/m·Ksourcetypical, 20 to 100 °C (generic Celanese UHMWPE) |
| 100 mm part over a 50 °C swing | 80µm growth12.5x less | 1,000µm growth |
| Specific heat | 500J/kg·Ksourceat RT | not sourced |
| Heats up and cools (diffusivity) | 3.8mm²/s | not sourced |
| Thermal shock resistance | 902W/m | not sourced |
| Melting point | not sourced | 130–138°CsourceDSC 10 K/min |
| Max service temperature | 871°Csourcecontinuous, scaling limit | 80°Csourcerecommended max constant operating temperature |
| Values for | 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 | 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 303 stronger than Plastic UHMWPE?
Stainless 303 is stronger: its yield strength is 275 MPa against 20 MPa for Plastic UHMWPE (13.8x).
Which is lighter, Stainless 303 or Plastic UHMWPE?
Plastic UHMWPE is lighter: 930 kg/m³ against 7,900 kg/m³ for Stainless 303.
Which is stiffer, Stainless 303 or Plastic UHMWPE?
Stainless 303 is stiffer: Young's modulus 200 GPa against 0.66 GPa for Plastic UHMWPE, so the same part in Stainless 303 deflects less under the same load.
Which is lighter for the same job, Stainless 303 or Plastic UHMWPE?
For the same stiffness or strength: Stainless 303 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 303 | Plastic UHMWPE |
|---|---|---|
| Stiff rod or tie (tension) | lighter | 35.7x heavier |
| Stiff beam (bending) | lighter | 2.05x heavier |
| Stiff panel or plate | 26% heavier | lighter |
| Strong rod or tie | lighter | 1.62x heavier |
| Strong beam | 48% heavier | lighter |
| Strong panel or plate | 2.29x 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 303 or Plastic UHMWPE?
Stainless 303 conducts heat better: 15 W/m·K against 0.4 W/m·K for Plastic UHMWPE.
Which expands less with temperature?
Stainless 303 expands less: 16 µm/m·K against 200 µm/m·K for Plastic UHMWPE.