Materials / Compare
Steel vs. Plastic UHMWPE
Compare Steel 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 | 385MPasourcetypical: mean of 20,295 A992 flange mill-test coupons (1998 SSPC survey), as reported by AISC | 20MPasourcetypical, tensile stress at yield ISO 527, 50 mm/min |
| Ultimate tensile strength | 505MPasourcetypical: mean of 20,295 A992 flange mill-test coupons (1998 SSPC survey) | 43MPasourcetypical, tensile stress at break ISO 527, 50 mm/min |
| Elongation at break | not sourced | 465%sourcetypical, nominal elongation at break ISO 527 |
| Young's modulus (stiffness) | 200GPasourcedesign value (AISC 360-16) | 0.66GPasourcetypical, tensile modulus ISO 527, 1 mm/min |
| Density | 7,850kg/m³sourcenominal (constructional data) | 930kg/m³sourcetypical |
| Strength to weight | 49kN·m/kg2.28x higher | 21.5kN·m/kg |
| Stiffness to weight | 25.5MN·m/kg35.9x higher | 0.71MN·m/kg |
| Poisson's ratio | 0.3sourcedesign value (AISC 360-16 Commentary) | not sourced |
| Shear modulus | 76.9GPa | not sourced |
| Bulk modulus | 167GPa | not sourced |
| Speed of sound | 5,048m/s | 842m/s |
| Thermal | ||
| Thermal conductivity | 48W/m·Ksourcenominal at 20 °C | 0.4W/m·Ksourcetypical, unfilled (narrative value, generic Celanese UHMWPE) |
| Thermal expansion | 12µm/m·Ksourcenominal (constructional data, no temperature range stated) | 200µm/m·Ksourcetypical, 20 to 100 °C (generic Celanese UHMWPE) |
| 100 mm part over a 50 °C swing | 60µm growth16.7x less | 1,000µm growth |
| Specific heat | 460–480J/kg·Ksourcebase material: EN S275JR unalloyed structural steel (the EN counterpart of A36), typical, 50/100 °C | not sourced |
| Heats up and cools (diffusivity) | 13mm²/s | not sourced |
| Thermal shock resistance | 5,390W/m | not sourced |
| Melting point | not sourced | 130–138°CsourceDSC 10 K/min |
| Max service temperature | not sourced | 80°Csourcerecommended max constant operating temperature |
| Values for | Generic structural steel, cited as ASTM A992 (the current US structural grade): ASTM A992 W-shapes; Fy/Fu specified minimums from AISC publications (AISC 360-16 Commentary; Modern Steel Construction); elastic constants AISC 360; physical constants from the bauforumstahl structural-steel EPD, which names A992 among covered product standards. | 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 Steel stronger than Plastic UHMWPE?
Steel is stronger: its yield strength is 385 MPa against 20 MPa for Plastic UHMWPE (19.3x).
Which is lighter, Steel or Plastic UHMWPE?
Plastic UHMWPE is lighter: 930 kg/m³ against 7,850 kg/m³ for Steel.
Which is stiffer, Steel or Plastic UHMWPE?
Steel is stiffer: Young's modulus 200 GPa against 0.66 GPa for Plastic UHMWPE, so the same part in Steel deflects less under the same load.
Which is lighter for the same job, Steel or Plastic UHMWPE?
For the same stiffness or strength: Steel 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 | Steel | Plastic UHMWPE |
|---|---|---|
| Stiff rod or tie (tension) | lighter | 35.9x heavier |
| Stiff beam (bending) | lighter | 2.06x heavier |
| Stiff panel or plate | 26% heavier | lighter |
| Strong rod or tie | lighter | 2.28x heavier |
| Strong beam | 18% heavier | lighter |
| Strong panel or plate | 1.92x 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, Steel or Plastic UHMWPE?
Steel conducts heat better: 48 W/m·K against 0.4 W/m·K for Plastic UHMWPE.
Which expands less with temperature?
Steel expands less: 12 µm/m·K against 200 µm/m·K for Plastic UHMWPE.