Materials / Compare
Stainless 303 vs. Stainless 304
Compare Stainless 303 vs. Stainless 304 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) | 241MPasourcetypical, annealed, 70 °F (21 °C) |
| Ultimate tensile strength | 585MPasourceOutokumpu typical | 586MPasourcetypical, annealed, 70 °F (21 °C) |
| Elongation at break | 35%sourceOutokumpu typical, A5 | 55%sourcetypical, annealed, in 2 in. (50.8 mm) |
| Young's modulus (stiffness) | 200GPasourceat RT (Table 12) | 193GPasourcetypical, in tension |
| Density | 7,900kg/m³sourceat RT | 8,030kg/m³sourcetypical |
| Strength to weight | 34.8kN·m/kg16% higher | 30kN·m/kg |
| Stiffness to weight | 25.3MN·m/kg5% higher | 24MN·m/kg |
| Poisson's ratio | 0.3sourcedesign value (structural stainless steels) | 0.3sourcedesign value (structural stainless steels) |
| Shear modulus | 76.9GPa4% stiffer in shear | 74.2GPa |
| Bulk modulus | 167GPa | 161GPa |
| Speed of sound | 5,032m/s | 4,903m/s |
| Thermal | ||
| Thermal conductivity | 15W/m·Ksourceat RT | 16.2W/m·Ksourceat 100 °C |
| Thermal expansion | 16µm/m·Ksourcemean, 20–100 °C | 16.9µm/m·Ksourcemean, 0–100 °C |
| 100 mm part over a 50 °C swing | 80µm growth6% less | 84.5µm growth |
| Specific heat | 500J/kg·Ksourceat RT | 500J/kg·Ksourcemean, 0–100 °C |
| Heats up and cools (diffusivity) | 3.8mm²/s | 4.03mm²/s6% faster |
| Thermal shock resistance | 902W/m8% more resistant | 838W/m |
| Melting point | not sourced | 1,399–1,454°Csourcemelting range |
| Max service temperature | 871°Csourcecontinuous, scaling limit | 899°Csourcecontinuous, oxidation (scaling) limit in air |
| 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 | 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 |
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 Stainless 304?
Stainless 303 is stronger: its yield strength is 275 MPa against 241 MPa for Stainless 304 (14%).
Which is lighter, Stainless 303 or Stainless 304?
Stainless 303 is lighter: 7,900 kg/m³ against 8,030 kg/m³ for Stainless 304.
Which is stiffer, Stainless 303 or Stainless 304?
Stainless 303 is stiffer: Young's modulus 200 GPa against 193 GPa for Stainless 304, so the same part in Stainless 303 deflects less under the same load.
Which is lighter for the same job, Stainless 303 or Stainless 304?
For the same stiffness or strength: Stainless 303 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 | Stainless 304 |
|---|---|---|
| Stiff rod or tie (tension) | lighter | 5% heavier |
| Stiff beam (bending) | lighter | 3% heavier |
| Stiff panel or plate | lighter | 3% heavier |
| Strong rod or tie | lighter | 16% heavier |
| Strong beam | lighter | 11% heavier |
| Strong panel or plate | lighter | 9% 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 303 or Stainless 304?
Stainless 304 conducts heat better: 16.2 W/m·K against 15 W/m·K for Stainless 303.
Which expands less with temperature?
Stainless 303 expands less: 16 µm/m·K against 16.9 µm/m·K for Stainless 304.