S21904 Stainless Steel vs. Nickel 684
S21904 stainless steel belongs to the iron alloys classification, while nickel 684 belongs to the nickel alloys. They have a modest 27% of their average alloy composition in common, which, by itself, doesn't mean much. There are 27 material properties with values for both materials. Properties with values for just one material (7, in this case) are not shown.
For each property being compared, the top bar is S21904 stainless steel and the bottom bar is nickel 684.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 210 to 300 | |
| 310 |
| Elastic (Young's, Tensile) Modulus, GPa | 200 | |
| 200 |
| Elongation at Break, % | 17 to 51 | |
| 11 |
| Fatigue Strength, MPa | 380 to 550 | |
| 390 |
| Poisson's Ratio | 0.28 | |
| 0.29 |
| Shear Modulus, GPa | 78 | |
| 76 |
| Shear Strength, MPa | 510 to 620 | |
| 710 |
| Tensile Strength: Ultimate (UTS), MPa | 700 to 1000 | |
| 1190 |
| Tensile Strength: Yield (Proof), MPa | 390 to 910 | |
| 800 |
Thermal Properties
| Latent Heat of Fusion, J/g | 290 | |
| 320 |
| Maximum Temperature: Mechanical, °C | 980 | |
| 1000 |
| Melting Completion (Liquidus), °C | 1400 | |
| 1370 |
| Melting Onset (Solidus), °C | 1350 | |
| 1320 |
| Specific Heat Capacity, J/kg-K | 480 | |
| 470 |
| Thermal Expansion, µm/m-K | 17 | |
| 13 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 15 | |
| 75 |
| Density, g/cm3 | 7.7 | |
| 8.3 |
| Embodied Carbon, kg CO2/kg material | 3.0 | |
| 10 |
| Embodied Energy, MJ/kg | 43 | |
| 140 |
| Embodied Water, L/kg | 160 | |
| 360 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 160 to 310 | |
| 120 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 380 to 2070 | |
| 1610 |
| Stiffness to Weight: Axial, points | 14 | |
| 13 |
| Stiffness to Weight: Bending, points | 25 | |
| 23 |
| Strength to Weight: Axial, points | 25 to 36 | |
| 40 |
| Strength to Weight: Bending, points | 23 to 29 | |
| 30 |
| Thermal Shock Resistance, points | 15 to 21 | |
| 34 |
Alloy Composition
| Aluminum (Al), % | 0 | |
| 2.5 to 3.3 |
| Boron (B), % | 0 | |
| 0.0030 to 0.010 |
| Carbon (C), % | 0 to 0.040 | |
| 0 to 0.15 |
| Chromium (Cr), % | 19 to 21.5 | |
| 15 to 20 |
| Cobalt (Co), % | 0 | |
| 13 to 20 |
| Copper (Cu), % | 0 | |
| 0 to 0.15 |
| Iron (Fe), % | 59.5 to 67.4 | |
| 0 to 4.0 |
| Manganese (Mn), % | 8.0 to 10 | |
| 0 to 0.75 |
| Molybdenum (Mo), % | 0 | |
| 3.0 to 5.0 |
| Nickel (Ni), % | 5.5 to 7.5 | |
| 42.7 to 64 |
| Nitrogen (N), % | 0.15 to 0.4 | |
| 0 |
| Phosphorus (P), % | 0 to 0.045 | |
| 0 to 0.015 |
| Silicon (Si), % | 0 to 1.0 | |
| 0 to 0.75 |
| Sulfur (S), % | 0 to 0.030 | |
| 0 to 0.015 |
| Titanium (Ti), % | 0 | |
| 2.5 to 3.3 |