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