Materials / Compare
Stainless 303 vs. Steel
Compare Stainless 303 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 | 275MPasourceOutokumpu typical (product P = hot rolled plate, transverse) | 385MPasourcetypical: mean of 20,295 A992 flange mill-test coupons (1998 SSPC survey), as reported by AISC |
| Ultimate tensile strength | 585MPasourceOutokumpu typical | 505MPasourcetypical: mean of 20,295 A992 flange mill-test coupons (1998 SSPC survey) |
| Elongation at break | 35%sourceOutokumpu typical, A5 | not sourced |
| Young's modulus (stiffness) | 200GPasourceat RT (Table 12) | 200GPasourcedesign value (AISC 360-16) |
| Density | 7,900kg/m³sourceat RT | 7,850kg/m³sourcenominal (constructional data) |
| Strength to weight | 34.8kN·m/kg | 49kN·m/kg41% higher |
| Stiffness to weight | 25.3MN·m/kg | 25.5MN·m/kg |
| Poisson's ratio | 0.3sourcedesign value (structural stainless steels) | 0.3sourcedesign value (AISC 360-16 Commentary) |
| Shear modulus | 76.9GPa | 76.9GPa |
| Bulk modulus | 167GPa | 167GPa |
| Speed of sound | 5,032m/s | 5,048m/s |
| Thermal | ||
| Thermal conductivity | 15W/m·Ksourceat RT | 48W/m·Ksourcenominal at 20 °C |
| Thermal expansion | 16µm/m·Ksourcemean, 20–100 °C | 12µm/m·Ksourcenominal (constructional data, no temperature range stated) |
| 100 mm part over a 50 °C swing | 80µm growth | 60µm growth33% less |
| Specific heat | 500J/kg·Ksourceat RT | 460–480J/kg·Ksourcebase material: EN S275JR unalloyed structural steel (the EN counterpart of A36), typical, 50/100 °C |
| Heats up and cools (diffusivity) | 3.8mm²/s | 13mm²/s3.43x faster |
| Thermal shock resistance | 902W/m | 5,390W/m5.97x 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 | 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 303 stronger than Steel?
Steel is stronger: its yield strength is 385 MPa against 275 MPa for Stainless 303 (40%).
Which is lighter, Stainless 303 or Steel?
Steel is lighter: 7,850 kg/m³ against 7,900 kg/m³ for Stainless 303.
Which is stiffer, Stainless 303 or Steel?
Stainless 303 is stiffer: Young's modulus 200 GPa against 200 GPa for Steel, so the same part in Stainless 303 deflects less under the same load.
Which is lighter for the same job, Stainless 303 or Steel?
For the same stiffness or strength: Steel is lighter for a strong rod or tie, strong beam, strong panel or plate.
| Part that must be | Stainless 303 | Steel |
|---|---|---|
| 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 | 41% heavier | lighter |
| Strong beam | 26% heavier | lighter |
| Strong panel or plate | 19% 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?
Steel conducts heat better: 48 W/m·K against 15 W/m·K for Stainless 303.
Which expands less with temperature?
Steel expands less: 12 µm/m·K against 16 µm/m·K for Stainless 303.