S21904 Stainless Steel vs. AISI 440A Stainless Steel
Both S21904 stainless steel and AISI 440A stainless steel are iron alloys. They have 81% of their average alloy composition in common. There are 31 material properties with values for both materials. Properties with values for just one material (2, in this case) are not shown.
For each property being compared, the top bar is S21904 stainless steel and the bottom bar is AISI 440A stainless steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 200 | |
| 200 |
| Elongation at Break, % | 17 to 51 | |
| 5.0 to 20 |
| Fatigue Strength, MPa | 380 to 550 | |
| 270 to 790 |
| Poisson's Ratio | 0.28 | |
| 0.28 |
| Shear Modulus, GPa | 78 | |
| 77 |
| Shear Strength, MPa | 510 to 620 | |
| 450 to 1040 |
| Tensile Strength: Ultimate (UTS), MPa | 700 to 1000 | |
| 730 to 1790 |
| Tensile Strength: Yield (Proof), MPa | 390 to 910 | |
| 420 to 1650 |
Thermal Properties
| Latent Heat of Fusion, J/g | 290 | |
| 280 |
| Maximum Temperature: Corrosion, °C | 430 | |
| 400 |
| Maximum Temperature: Mechanical, °C | 980 | |
| 760 |
| Melting Completion (Liquidus), °C | 1400 | |
| 1480 |
| Melting Onset (Solidus), °C | 1350 | |
| 1370 |
| Specific Heat Capacity, J/kg-K | 480 | |
| 480 |
| Thermal Conductivity, W/m-K | 14 | |
| 23 |
| Thermal Expansion, µm/m-K | 17 | |
| 10 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 2.5 | |
| 2.5 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 2.9 | |
| 2.9 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 15 | |
| 9.0 |
| Density, g/cm3 | 7.7 | |
| 7.7 |
| Embodied Carbon, kg CO2/kg material | 3.0 | |
| 2.2 |
| Embodied Energy, MJ/kg | 43 | |
| 31 |
| Embodied Water, L/kg | 160 | |
| 120 |
Common Calculations
| PREN (Pitting Resistance) | 25 | |
| 18 |
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 160 to 310 | |
| 87 to 120 |
| Stiffness to Weight: Axial, points | 14 | |
| 14 |
| Stiffness to Weight: Bending, points | 25 | |
| 25 |
| Strength to Weight: Axial, points | 25 to 36 | |
| 26 to 65 |
| Strength to Weight: Bending, points | 23 to 29 | |
| 23 to 43 |
| Thermal Diffusivity, mm2/s | 3.8 | |
| 6.2 |
| Thermal Shock Resistance, points | 15 to 21 | |
| 26 to 65 |
Alloy Composition
| Carbon (C), % | 0 to 0.040 | |
| 0.6 to 0.75 |
| Chromium (Cr), % | 19 to 21.5 | |
| 16 to 18 |
| Iron (Fe), % | 59.5 to 67.4 | |
| 78.4 to 83.4 |
| Manganese (Mn), % | 8.0 to 10 | |
| 0 to 1.0 |
| Molybdenum (Mo), % | 0 | |
| 0 to 0.75 |
| Nickel (Ni), % | 5.5 to 7.5 | |
| 0 |
| Nitrogen (N), % | 0.15 to 0.4 | |
| 0 |
| Phosphorus (P), % | 0 to 0.045 | |
| 0 to 0.040 |
| Silicon (Si), % | 0 to 1.0 | |
| 0 to 1.0 |
| Sulfur (S), % | 0 to 0.030 | |
| 0 to 0.015 |