S21900 Stainless Steel vs. R30035 Cobalt
S21900 stainless steel belongs to the iron alloys classification, while R30035 cobalt belongs to the cobalt alloys. They have a modest 27% of their average alloy composition in common, which, by itself, doesn't mean much. There are 29 material properties with values for both materials. Properties with values for just one material (5, in this case) are not shown.
For each property being compared, the top bar is S21900 stainless steel and the bottom bar is R30035 cobalt.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 200 | |
| 220 to 230 |
| Elongation at Break, % | 50 | |
| 9.0 to 46 |
| Fatigue Strength, MPa | 380 | |
| 170 to 740 |
| Poisson's Ratio | 0.28 | |
| 0.29 |
| Reduction in Area, % | 57 | |
| 40 to 74 |
| Shear Modulus, GPa | 78 | |
| 84 to 89 |
| Tensile Strength: Ultimate (UTS), MPa | 710 | |
| 900 to 1900 |
| Tensile Strength: Yield (Proof), MPa | 390 | |
| 300 to 1650 |
Thermal Properties
| Latent Heat of Fusion, J/g | 290 | |
| 320 |
| Melting Completion (Liquidus), °C | 1400 | |
| 1440 |
| Melting Onset (Solidus), °C | 1350 | |
| 1320 |
| Specific Heat Capacity, J/kg-K | 480 | |
| 440 |
| Thermal Conductivity, W/m-K | 14 | |
| 11 |
| Thermal Expansion, µm/m-K | 17 | |
| 13 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 2.5 | |
| 1.7 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 2.9 | |
| 1.8 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 15 | |
| 100 |
| Density, g/cm3 | 7.7 | |
| 8.7 |
| Embodied Carbon, kg CO2/kg material | 3.0 | |
| 10 |
| Embodied Energy, MJ/kg | 43 | |
| 140 |
| Embodied Water, L/kg | 160 | |
| 410 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 300 | |
| 160 to 320 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 380 | |
| 210 to 5920 |
| Stiffness to Weight: Axial, points | 14 | |
| 14 to 15 |
| Stiffness to Weight: Bending, points | 25 | |
| 23 to 24 |
| Strength to Weight: Axial, points | 26 | |
| 29 to 61 |
| Strength to Weight: Bending, points | 23 | |
| 24 to 39 |
| Thermal Diffusivity, mm2/s | 3.8 | |
| 3.0 |
| Thermal Shock Resistance, points | 15 | |
| 23 to 46 |
Alloy Composition
| Boron (B), % | 0 | |
| 0 to 0.015 |
| Carbon (C), % | 0 to 0.080 | |
| 0 to 0.025 |
| Chromium (Cr), % | 19 to 21.5 | |
| 19 to 21 |
| Cobalt (Co), % | 0 | |
| 29.1 to 39 |
| Iron (Fe), % | 59.4 to 67.4 | |
| 0 to 1.0 |
| Manganese (Mn), % | 8.0 to 10 | |
| 0 to 0.15 |
| Molybdenum (Mo), % | 0 | |
| 9.0 to 10.5 |
| Nickel (Ni), % | 5.5 to 7.5 | |
| 33 to 37 |
| 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 0.15 |
| Sulfur (S), % | 0 to 0.030 | |
| 0 to 0.010 |
| Titanium (Ti), % | 0 | |
| 0 to 1.0 |