Materials / Compare
Plastic HDPE vs. Steel A992
Compare Plastic HDPE vs. Steel A992 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 | 24MPasourcetypical, tensile stress at yield 23 °C, 50 mm/min ISO 527 | 385MPasourcetypical: mean of 20,295 A992 flange mill-test coupons (1998 SSPC survey), as reported by AISC |
| Ultimate tensile strength | not sourced | 505MPasourcetypical: mean of 20,295 A992 flange mill-test coupons (1998 SSPC survey) |
| Elongation at break | not sourced | not sourced |
| Young's modulus (stiffness) | 0.9GPasourcetypical, tensile modulus 23 °C ISO 527 | 200GPasourcedesign value (AISC 360-16) |
| Density | 950kg/m³sourcetypical, ISO 1183 | 7,850kg/m³sourcenominal (constructional data) |
| Strength to weight | 25.3kN·m/kg | 49kN·m/kg1.94x higher |
| Stiffness to weight | 0.947MN·m/kg | 25.5MN·m/kg26.9x higher |
| Poisson's ratio | 0.4–0.45sourcebase material: high-density polyethylene family (INEOS Olefins & Polymers USA, Typical Engineering Properties of HDPE) | 0.3sourcedesign value (AISC 360-16 Commentary) |
| Shear modulus | 0.316GPa | 76.9GPa244x stiffer in shear |
| Bulk modulus | 2GPa | 167GPa |
| Speed of sound | 973m/s | 5,048m/s |
| Thermal | ||
| Thermal conductivity | 0.4–0.49W/m·Ksourcebase material: high-density polyethylene family (INEOS Olefins & Polymers USA, Typical Engineering Properties of HDPE) | 48W/m·Ksourcenominal at 20 °C |
| Thermal expansion | 120µm/m·Ksourcebase material: high-density polyethylene family (INEOS Olefins & Polymers USA, Typical Engineering Properties of HDPE) | 12µm/m·Ksourcenominal (constructional data, no temperature range stated) |
| 100 mm part over a 50 °C swing | 600µm growth | 60µm growth10x less |
| Specific heat | 2,250J/kg·Ksourcebase material: high-density polyethylene family (INEOS Olefins & Polymers USA, Typical Engineering Properties of HDPE) | 460–480J/kg·Ksourcebase material: EN S275JR unalloyed structural steel (the EN counterpart of A36), typical, 50/100 °C |
| Heats up and cools (diffusivity) | 0.208mm²/s | 13mm²/s62.5x faster |
| Thermal shock resistance | 56.9W/m | 5,390W/m94.8x more resistant |
| Values for | LyondellBasell Hostalen 23050 B high density polyethylene, typical ISO values | 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. |
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 HDPE stronger than Steel A992?
Steel A992 is stronger: its yield strength is 385 MPa against 24 MPa for Plastic HDPE (16x).
Which is lighter, Plastic HDPE or Steel A992?
Plastic HDPE is lighter: 950 kg/m³ against 7,850 kg/m³ for Steel A992.
Which is stiffer, Plastic HDPE or Steel A992?
Steel A992 is stiffer: Young's modulus 200 GPa against 0.9 GPa for Plastic HDPE, so the same part in Steel A992 deflects less under the same load.
Which is lighter for the same job, Plastic HDPE or Steel A992?
For the same stiffness or strength: Plastic HDPE is lighter for a stiff panel or plate, strong beam, strong panel or plate; Steel A992 is lighter for a stiff rod or tie (tension), stiff beam (bending), strong rod or tie.
| Part that must be | Plastic HDPE | Steel A992 |
|---|---|---|
| Stiff rod or tie (tension) | 26.9x heavier | lighter |
| Stiff beam (bending) | 1.8x heavier | lighter |
| Stiff panel or plate | lighter | 36% heavier |
| Strong rod or tie | 1.94x heavier | lighter |
| Strong beam | lighter | 30% heavier |
| Strong panel or plate | lighter | 2.06x 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 HDPE or Steel A992?
Steel A992 conducts heat better: 48 W/m·K against 0.445 W/m·K for Plastic HDPE.
Which expands less with temperature?
Steel A992 expands less: 12 µm/m·K against 120 µm/m·K for Plastic HDPE.