Materials / Compare
Stainless 304 vs. Steel
Compare Stainless 304 vs. Steel 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) | 385MPasourcetypical: mean of 20,295 A992 flange mill-test coupons (1998 SSPC survey), as reported by AISC |
| Ultimate tensile strength | 586MPasourcetypical, annealed, 70 °F (21 °C) | 505MPasourcetypical: mean of 20,295 A992 flange mill-test coupons (1998 SSPC survey) |
| Elongation at break | 55%sourcetypical, annealed, in 2 in. (50.8 mm) | not sourced |
| Young's modulus (stiffness) | 193GPasourcetypical, in tension | 200GPasourcedesign value (AISC 360-16) |
| Density | 8,030kg/m³sourcetypical | 7,850kg/m³sourcenominal (constructional data) |
| Strength to weight | 30kN·m/kg | 49kN·m/kg1.63x higher |
| Stiffness to weight | 24MN·m/kg | 25.5MN·m/kg6% higher |
| Poisson's ratio | 0.3sourcedesign value (structural stainless steels) | 0.3sourcedesign value (AISC 360-16 Commentary) |
| Shear modulus | 74.2GPa | 76.9GPa4% stiffer in shear |
| Bulk modulus | 161GPa | 167GPa |
| Speed of sound | 4,903m/s | 5,048m/s |
| Thermal | ||
| Thermal conductivity | 16.2W/m·Ksourceat 100 °C | 48W/m·Ksourcenominal at 20 °C |
| Thermal expansion | 16.9µm/m·Ksourcemean, 0–100 °C | 12µm/m·Ksourcenominal (constructional data, no temperature range stated) |
| 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·Ksourcebase material: EN S275JR unalloyed structural steel (the EN counterpart of A36), typical, 50/100 °C |
| Heats up and cools (diffusivity) | 4.03mm²/s | 13mm²/s3.22x faster |
| Thermal shock resistance | 838W/m | 5,390W/m6.43x 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 | Generic structural steel, cited as ASTM A992 (the current US structural grade): ASTM A992 W-shapes; Fy/Fu specified minimums from AISC publications (AISC 360-16 Commentary; Modern Steel Construction); elastic constants AISC 360; physical constants from the bauforumstahl structural-steel EPD, which names A992 among covered product standards. |
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?
Steel is stronger: its yield strength is 385 MPa against 241 MPa for Stainless 304 (1.6x).
Which is lighter, Stainless 304 or Steel?
Steel is lighter: 7,850 kg/m³ against 8,030 kg/m³ for Stainless 304.
Which is stiffer, Stainless 304 or Steel?
Steel is stiffer: Young's modulus 200 GPa against 193 GPa for Stainless 304, so the same part in Steel deflects less under the same load.
Which is lighter for the same job, Stainless 304 or Steel?
For the same stiffness or strength: Steel 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 |
|---|---|---|
| Stiff rod or tie (tension) | 6% heavier | lighter |
| Stiff beam (bending) | 4% heavier | lighter |
| Stiff panel or plate | 4% heavier | lighter |
| Strong rod or tie | 1.63x heavier | lighter |
| Strong beam | 40% heavier | lighter |
| Strong panel or plate | 29% 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?
Steel conducts heat better: 48 W/m·K against 16.2 W/m·K for Stainless 304.
Which expands less with temperature?
Steel expands less: 12 µm/m·K against 16.9 µm/m·K for Stainless 304.