S21900 Stainless Steel vs. AISI 418 Stainless Steel
Both S21900 stainless steel and AISI 418 stainless steel are iron alloys. They have 79% of their average alloy composition in common.
For each property being compared, the top bar is S21900 stainless steel and the bottom bar is AISI 418 stainless steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 220 | |
| 330 |
| Elastic (Young's, Tensile) Modulus, GPa | 200 | |
| 200 |
| Elongation at Break, % | 50 | |
| 17 |
| Fatigue Strength, MPa | 380 | |
| 520 |
| Poisson's Ratio | 0.28 | |
| 0.28 |
| Reduction in Area, % | 57 | |
| 50 |
| Shear Modulus, GPa | 78 | |
| 77 |
| Shear Strength, MPa | 510 | |
| 680 |
| Tensile Strength: Ultimate (UTS), MPa | 710 | |
| 1100 |
| Tensile Strength: Yield (Proof), MPa | 390 | |
| 850 |
Thermal Properties
| Latent Heat of Fusion, J/g | 290 | |
| 270 |
| Maximum Temperature: Corrosion, °C | 420 | |
| 390 |
| Maximum Temperature: Mechanical, °C | 980 | |
| 770 |
| Melting Completion (Liquidus), °C | 1400 | |
| 1500 |
| Melting Onset (Solidus), °C | 1350 | |
| 1460 |
| Specific Heat Capacity, J/kg-K | 480 | |
| 470 |
| Thermal Conductivity, W/m-K | 14 | |
| 25 |
| Thermal Expansion, µm/m-K | 17 | |
| 10 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 2.5 | |
| 2.8 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 2.9 | |
| 3.1 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 15 | |
| 15 |
| Density, g/cm3 | 7.7 | |
| 8.0 |
| Embodied Carbon, kg CO2/kg material | 3.0 | |
| 2.9 |
| Embodied Energy, MJ/kg | 43 | |
| 41 |
| Embodied Water, L/kg | 160 | |
| 110 |
Common Calculations
| PREN (Pitting Resistance) | 25 | |
| 19 |
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 300 | |
| 170 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 380 | |
| 1830 |
| Stiffness to Weight: Axial, points | 14 | |
| 14 |
| Stiffness to Weight: Bending, points | 25 | |
| 24 |
| Strength to Weight: Axial, points | 26 | |
| 38 |
| Strength to Weight: Bending, points | 23 | |
| 29 |
| Thermal Diffusivity, mm2/s | 3.8 | |
| 6.7 |
| Thermal Shock Resistance, points | 15 | |
| 40 |
Alloy Composition
| Carbon (C), % | 0 to 0.080 | |
| 0.15 to 0.2 |
| Chromium (Cr), % | 19 to 21.5 | |
| 12 to 14 |
| Iron (Fe), % | 59.4 to 67.4 | |
| 78.5 to 83.6 |
| Manganese (Mn), % | 8.0 to 10 | |
| 0 to 0.5 |
| Molybdenum (Mo), % | 0 | |
| 0 to 0.5 |
| Nickel (Ni), % | 5.5 to 7.5 | |
| 1.8 to 2.2 |
| 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 0.5 |
| Sulfur (S), % | 0 to 0.030 | |
| 0 to 0.030 |
| Tungsten (W), % | 0 | |
| 2.5 to 3.5 |