Materials / Compare
Stainless 303 vs. Steel AISI 1045
Compare Stainless 303 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 | 275MPasourceOutokumpu typical (product P = hot rolled plate, transverse) | 531MPasourceproducer-stated, cold drawn |
| Ultimate tensile strength | 585MPasourceOutokumpu typical | 627MPasourceproducer-stated, cold drawn |
| Elongation at break | 35%sourceOutokumpu typical, A5 | 12%sourcein 2 in (50.8 mm) |
| Young's modulus (stiffness) | 200GPasourceat RT (Table 12) | 210GPasourcetypical |
| Density | 7,900kg/m³sourceat RT | 7,800kg/m³sourcetypical |
| Strength to weight | 34.8kN·m/kg | 68.1kN·m/kg1.96x higher |
| Stiffness to weight | 25.3MN·m/kg | 26.9MN·m/kg6% higher |
| Poisson's ratio | 0.3sourcedesign value (structural stainless steels) | 0.3sourcetypical |
| Shear modulus | 76.9GPa | 80.8GPa5% stiffer in shear |
| Bulk modulus | 167GPa | 175GPa |
| Speed of sound | 5,032m/s | 5,189m/s |
| Thermal | ||
| Thermal conductivity | 15W/m·Ksourceat RT | 40–45W/m·Ksourcetypical range, ambient |
| Thermal expansion | 16µm/m·Ksourcemean, 20–100 °C | 12µm/m·Ksourcetypical, mean 20-300 °C |
| 100 mm part over a 50 °C swing | 80µm growth | 60µm growth33% less |
| Specific heat | 500J/kg·Ksourceat RT | 460–480J/kg·Ksourcetypical range, 50/100 °C |
| Heats up and cools (diffusivity) | 3.8mm²/s | 11.6mm²/s3.05x faster |
| Thermal shock resistance | 902W/m | 6,269W/m6.95x more resistant |
| Max service temperature | 871°Csourcecontinuous, scaling limit | not sourced |
| Values for | 1.4305 / UNS S30300, Outokumpu typical values (hot rolled, solution annealed) from 'Steel Grades, Properties and Global Standards'; max service from Carpenter CarTech 303 datasheet | 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 303 stronger than Steel AISI 1045?
Steel AISI 1045 is stronger: its yield strength is 531 MPa against 275 MPa for Stainless 303 (1.93x).
Which is lighter, Stainless 303 or Steel AISI 1045?
Steel AISI 1045 is lighter: 7,800 kg/m³ against 7,900 kg/m³ for Stainless 303.
Which is stiffer, Stainless 303 or Steel AISI 1045?
Steel AISI 1045 is stiffer: Young's modulus 210 GPa against 200 GPa for Stainless 303, so the same part in Steel AISI 1045 deflects less under the same load.
Which is lighter for the same job, Stainless 303 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 303 | Steel AISI 1045 |
|---|---|---|
| Stiff rod or tie (tension) | 6% heavier | lighter |
| Stiff beam (bending) | 4% heavier | lighter |
| Stiff panel or plate | 3% heavier | lighter |
| Strong rod or tie | 1.96x heavier | lighter |
| Strong beam | 1.57x heavier | lighter |
| Strong panel or plate | 41% 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 303 or Steel AISI 1045?
Steel AISI 1045 conducts heat better: 42.5 W/m·K against 15 W/m·K for Stainless 303.
Which expands less with temperature?
Steel AISI 1045 expands less: 12 µm/m·K against 16 µm/m·K for Stainless 303.