Materials / Compare
Plastic HDPE vs. Stainless 17-4PH
Compare Plastic HDPE vs. Stainless 17-4PH 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 | 1,275MPasourcetypical, transverse, sheet/strip |
| Ultimate tensile strength | not sourced | 1,379MPasourcetypical, transverse, sheet/strip |
| Elongation at break | not sourced | 9%sourcetypical, transverse, in 2 in. (50.8 mm) |
| Young's modulus (stiffness) | 0.9GPasourcetypical, tensile modulus 23 °C ISO 527 | 197GPasourceH 900 |
| Density | 950kg/m³sourcetypical, ISO 1183 | 7,800kg/m³sourceH 900 |
| Strength to weight | 25.3kN·m/kg | 163kN·m/kg6.47x higher |
| Stiffness to weight | 0.947MN·m/kg | 25.3MN·m/kg26.7x higher |
| Poisson's ratio | 0.4–0.45sourcebase material: high-density polyethylene family (INEOS Olefins & Polymers USA, Typical Engineering Properties of HDPE) | 0.272sourceH 900 (column) |
| Shear modulus | 0.316GPa | 77.4GPa245x stiffer in shear |
| Bulk modulus | 2GPa | 144GPa |
| Speed of sound | 973m/s | 5,026m/s |
| Thermal | ||
| Thermal conductivity | 0.4–0.49W/m·Ksourcebase material: high-density polyethylene family (INEOS Olefins & Polymers USA, Typical Engineering Properties of HDPE) | 17.9W/m·Ksourceat 149 °C (300 °F), H 900 |
| Thermal expansion | 120µm/m·Ksourcebase material: high-density polyethylene family (INEOS Olefins & Polymers USA, Typical Engineering Properties of HDPE) | 10.8µm/m·Ksourcemean, 21–93 °C (70–200 °F), H 900 |
| 100 mm part over a 50 °C swing | 600µm growth | 54µm growth11.1x less |
| Specific heat | 2,250J/kg·Ksourcebase material: high-density polyethylene family (INEOS Olefins & Polymers USA, Typical Engineering Properties of HDPE) | 460J/kg·Ksourcemean, 0–100 °C, H 900 |
| Heats up and cools (diffusivity) | 0.208mm²/s | 4.99mm²/s24x faster |
| Thermal shock resistance | 56.9W/m | 7,809W/m137x more resistant |
| Max service temperature | not sourced | 316°Csourcestrength-retention limit (not oxidation) |
| Values for | LyondellBasell Hostalen 23050 B high density polyethylene, typical ISO values | Cleveland-Cliffs 17-4 PH, Condition H 900, sheet/strip, transverse (Product Data Bulletin, May 2021) |
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 Stainless 17-4PH?
Stainless 17-4PH is stronger: its yield strength is 1,275 MPa against 24 MPa for Plastic HDPE (53.1x).
Which is lighter, Plastic HDPE or Stainless 17-4PH?
Plastic HDPE is lighter: 950 kg/m³ against 7,800 kg/m³ for Stainless 17-4PH.
Which is stiffer, Plastic HDPE or Stainless 17-4PH?
Stainless 17-4PH is stiffer: Young's modulus 197 GPa against 0.9 GPa for Plastic HDPE, so the same part in Stainless 17-4PH deflects less under the same load.
Which is lighter for the same job, Plastic HDPE or Stainless 17-4PH?
For the same stiffness or strength: Plastic HDPE is lighter for a stiff panel or plate, strong panel or plate; Stainless 17-4PH is lighter for a stiff rod or tie (tension), stiff beam (bending), strong rod or tie, strong beam.
| Part that must be | Plastic HDPE | Stainless 17-4PH |
|---|---|---|
| Stiff rod or tie (tension) | 26.7x heavier | lighter |
| Stiff beam (bending) | 1.8x heavier | lighter |
| Stiff panel or plate | lighter | 36% heavier |
| Strong rod or tie | 6.47x heavier | lighter |
| Strong beam | 1.72x heavier | lighter |
| Strong panel or plate | lighter | 13% 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 Stainless 17-4PH?
Stainless 17-4PH conducts heat better: 17.9 W/m·K against 0.445 W/m·K for Plastic HDPE.
Which expands less with temperature?
Stainless 17-4PH expands less: 10.8 µm/m·K against 120 µm/m·K for Plastic HDPE.