Materials / Compare
Stainless 17-4PH vs. Steel AISI 1018
Compare Stainless 17-4PH vs. Steel AISI 1018 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 | 1,275MPasourcetypical, transverse, sheet/strip | 372MPasourceproducer-stated, cold drawn |
| Ultimate tensile strength | 1,379MPasourcetypical, transverse, sheet/strip | 441MPasourceproducer-stated, cold drawn |
| Elongation at break | 9%sourcetypical, transverse, in 2 in. (50.8 mm) | 15%sourcein 2 in (50.8 mm) |
| Young's modulus (stiffness) | 197GPasourceH 900 | 200GPasourcebase material: AISI 1025 plain carbon steel (MIL-HDBK-5J design value; ASTM A108 bar is the cold-finished carbon-steel bar spec that also covers 1018) |
| Density | 7,800kg/m³sourceH 900 | 7,861kg/m³sourcebase material: AISI 1025 plain carbon steel (MIL-HDBK-5J design value; ASTM A108 bar is the cold-finished carbon-steel bar spec that also covers 1018) |
| Strength to weight | 163kN·m/kg3.45x higher | 47.3kN·m/kg |
| Stiffness to weight | 25.3MN·m/kg | 25.4MN·m/kg |
| Poisson's ratio | 0.272sourceH 900 (column) | 0.32sourcebase material: AISI 1025 plain carbon steel (MIL-HDBK-5J design value; ASTM A108 bar is the cold-finished carbon-steel bar spec that also covers 1018) |
| Shear modulus | 77.4GPa2% stiffer in shear | 75.7GPa |
| Bulk modulus | 144GPa | 185GPa |
| Speed of sound | 5,026m/s | 5,043m/s |
| Thermal | ||
| Thermal conductivity | 17.9W/m·Ksourceat 149 °C (300 °F), H 900 | 51.9W/m·Ksourcebase material: AISI 1025 plain carbon steel (MIL-HDBK-5J design value; ASTM A108 bar is the cold-finished carbon-steel bar spec that also covers 1018) |
| Thermal expansion | 10.8µm/m·Ksourcemean, 21–93 °C (70–200 °F), H 900 | 12µm/m·Ksourcebase material: unalloyed carbon steel, Ovako family table (S275JR, 'none alloyed structural steels', C <= 0.21%); mean 20-300 °C |
| 100 mm part over a 50 °C swing | 54µm growth11% less | 60µm growth |
| Specific heat | 460J/kg·Ksourcemean, 0–100 °C, H 900 | 486J/kg·Ksourcebase material: AISI 1025 plain carbon steel (MIL-HDBK-5J design value; ASTM A108 bar is the cold-finished carbon-steel bar spec that also covers 1018) |
| Heats up and cools (diffusivity) | 4.99mm²/s | 13.6mm²/s2.72x faster |
| Thermal shock resistance | 7,809W/m43% more resistant | 5,473W/m |
| Max service temperature | 316°Csourcestrength-retention limit (not oxidation) | not sourced |
| Values for | Cleveland-Cliffs 17-4 PH, Condition H 900, sheet/strip, transverse (Product Data Bulletin, May 2021) | AISI 1018 cold drawn bar (Niagara LaSalle, cold-finished bar producer) |
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 17-4PH stronger than Steel AISI 1018?
Stainless 17-4PH is stronger: its yield strength is 1,275 MPa against 372 MPa for Steel AISI 1018 (3.43x).
Which is lighter, Stainless 17-4PH or Steel AISI 1018?
Stainless 17-4PH is lighter: 7,800 kg/m³ against 7,861 kg/m³ for Steel AISI 1018.
Which is stiffer, Stainless 17-4PH or Steel AISI 1018?
Steel AISI 1018 is stiffer: Young's modulus 200 GPa against 197 GPa for Stainless 17-4PH, so the same part in Steel AISI 1018 deflects less under the same load.
Which is lighter for the same job, Stainless 17-4PH or Steel AISI 1018?
For the same stiffness or strength: Stainless 17-4PH is lighter for a strong rod or tie, strong beam, strong panel or plate.
| Part that must be | Stainless 17-4PH | Steel AISI 1018 |
|---|---|---|
| Stiff rod or tie (tension) | about equal | about equal |
| Stiff beam (bending) | about equal | about equal |
| Stiff panel or plate | about equal | about equal |
| Strong rod or tie | lighter | 3.45x heavier |
| Strong beam | lighter | 2.29x heavier |
| Strong panel or plate | lighter | 1.87x 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, Stainless 17-4PH or Steel AISI 1018?
Steel AISI 1018 conducts heat better: 51.9 W/m·K against 17.9 W/m·K for Stainless 17-4PH.
Which expands less with temperature?
Stainless 17-4PH expands less: 10.8 µm/m·K against 12 µm/m·K for Steel AISI 1018.