Materials / Compare
Stainless 304 vs. Steel AISI 1045
Compare Stainless 304 vs. Steel AISI 1045 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 | 241MPasourcetypical, annealed, 70 °F (21 °C) | 531MPasourceproducer-stated, cold drawn |
| Ultimate tensile strength | 586MPasourcetypical, annealed, 70 °F (21 °C) | 627MPasourceproducer-stated, cold drawn |
| Elongation at break | 55%sourcetypical, annealed, in 2 in. (50.8 mm) | 12%sourcein 2 in (50.8 mm) |
| Young's modulus (stiffness) | 193GPasourcetypical, in tension | 210GPasourcetypical |
| Density | 8,030kg/m³sourcetypical | 7,800kg/m³sourcetypical |
| Strength to weight | 30kN·m/kg | 68.1kN·m/kg2.27x higher |
| Stiffness to weight | 24MN·m/kg | 26.9MN·m/kg12% higher |
| Poisson's ratio | 0.3sourcedesign value (structural stainless steels) | 0.3sourcetypical |
| Shear modulus | 74.2GPa | 80.8GPa9% stiffer in shear |
| Bulk modulus | 161GPa | 175GPa |
| Speed of sound | 4,903m/s | 5,189m/s |
| Thermal | ||
| Thermal conductivity | 16.2W/m·Ksourceat 100 °C | 40–45W/m·Ksourcetypical range, ambient |
| Thermal expansion | 16.9µm/m·Ksourcemean, 0–100 °C | 12µm/m·Ksourcetypical, mean 20-300 °C |
| 100 mm part over a 50 °C swing | 84.5µm growth | 60µm growth41% less |
| Specific heat | 500J/kg·Ksourcemean, 0–100 °C | 460–480J/kg·Ksourcetypical range, 50/100 °C |
| Heats up and cools (diffusivity) | 4.03mm²/s | 11.6mm²/s2.87x faster |
| Thermal shock resistance | 838W/m | 6,269W/m7.48x more resistant |
| Melting point | 1,399–1,454°Csourcemelting range | not sourced |
| Max service temperature | 899°Csourcecontinuous, oxidation (scaling) limit in air | not sourced |
| Values for | Type 304, annealed flat-rolled (Cleveland-Cliffs 304/304L Product Data Bulletin, May 2021); Poisson's ratio from the Nickel Institute/SCI structural stainless design manual | AISI 1045 cold drawn bar (Niagara LaSalle) for mechanical; Ovako C45 (lists 'SAE 1045' as a similar designation) for physical constants |
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 304 stronger than Steel AISI 1045?
Steel AISI 1045 is stronger: its yield strength is 531 MPa against 241 MPa for Stainless 304 (2.2x).
Which is lighter, Stainless 304 or Steel AISI 1045?
Steel AISI 1045 is lighter: 7,800 kg/m³ against 8,030 kg/m³ for Stainless 304.
Which is stiffer, Stainless 304 or Steel AISI 1045?
Steel AISI 1045 is stiffer: Young's modulus 210 GPa against 193 GPa for Stainless 304, so the same part in Steel AISI 1045 deflects less under the same load.
Which is lighter for the same job, Stainless 304 or Steel AISI 1045?
For the same stiffness or strength: Steel AISI 1045 is lighter for a stiff rod or tie (tension), stiff beam (bending), stiff panel or plate, strong rod or tie, strong beam, strong panel or plate.
| Part that must be | Stainless 304 | Steel AISI 1045 |
|---|---|---|
| Stiff rod or tie (tension) | 12% heavier | lighter |
| Stiff beam (bending) | 7% heavier | lighter |
| Stiff panel or plate | 6% heavier | lighter |
| Strong rod or tie | 2.27x heavier | lighter |
| Strong beam | 1.74x heavier | lighter |
| Strong panel or plate | 1.53x 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, Stainless 304 or Steel AISI 1045?
Steel AISI 1045 conducts heat better: 42.5 W/m·K against 16.2 W/m·K for Stainless 304.
Which expands less with temperature?
Steel AISI 1045 expands less: 12 µm/m·K against 16.9 µm/m·K for Stainless 304.