S20910 Stainless Steel vs. R30021 Cobalt
S20910 stainless steel belongs to the iron alloys classification, while R30021 cobalt belongs to the cobalt alloys. They have a modest 29% of their average alloy composition in common, which, by itself, doesn't mean much. There are 25 material properties with values for both materials. Properties with values for just one material (11, in this case) are not shown.
For each property being compared, the top bar is S20910 stainless steel and the bottom bar is R30021 cobalt.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 200 | |
| 220 |
| Elongation at Break, % | 14 to 39 | |
| 9.0 |
| Fatigue Strength, MPa | 310 to 460 | |
| 250 |
| Poisson's Ratio | 0.28 | |
| 0.29 |
| Shear Modulus, GPa | 79 | |
| 86 |
| Tensile Strength: Ultimate (UTS), MPa | 780 to 940 | |
| 700 |
| Tensile Strength: Yield (Proof), MPa | 430 to 810 | |
| 500 |
Thermal Properties
| Latent Heat of Fusion, J/g | 300 | |
| 330 |
| Melting Completion (Liquidus), °C | 1420 | |
| 1350 |
| Melting Onset (Solidus), °C | 1380 | |
| 1190 |
| Specific Heat Capacity, J/kg-K | 480 | |
| 450 |
| Thermal Conductivity, W/m-K | 13 | |
| 15 |
| Thermal Expansion, µm/m-K | 16 | |
| 11 |
Otherwise Unclassified Properties
| Density, g/cm3 | 7.8 | |
| 8.4 |
| Embodied Carbon, kg CO2/kg material | 4.8 | |
| 8.0 |
| Embodied Energy, MJ/kg | 68 | |
| 110 |
| Embodied Water, L/kg | 180 | |
| 520 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 120 to 260 | |
| 57 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 460 to 1640 | |
| 570 |
| Stiffness to Weight: Axial, points | 14 | |
| 15 |
| Stiffness to Weight: Bending, points | 25 | |
| 24 |
| Strength to Weight: Axial, points | 28 to 33 | |
| 23 |
| Strength to Weight: Bending, points | 24 to 27 | |
| 21 |
| Thermal Diffusivity, mm2/s | 3.6 | |
| 3.8 |
| Thermal Shock Resistance, points | 17 to 21 | |
| 21 |
Alloy Composition
| Carbon (C), % | 0 to 0.060 | |
| 0.2 to 0.35 |
| Chromium (Cr), % | 20.5 to 23.5 | |
| 26 to 29 |
| Cobalt (Co), % | 0 | |
| 61.7 to 67.3 |
| Iron (Fe), % | 52.1 to 62.1 | |
| 0 to 3.0 |
| Manganese (Mn), % | 4.0 to 6.0 | |
| 0 |
| Molybdenum (Mo), % | 1.5 to 3.0 | |
| 4.5 to 6.0 |
| Nickel (Ni), % | 11.5 to 13.5 | |
| 2.0 to 3.0 |
| Niobium (Nb), % | 0.1 to 0.3 | |
| 0 |
| Nitrogen (N), % | 0.2 to 0.4 | |
| 0 |
| Phosphorus (P), % | 0 to 0.040 | |
| 0 |
| Silicon (Si), % | 0 to 0.75 | |
| 0 to 1.5 |
| Sulfur (S), % | 0 to 0.030 | |
| 0 |
| Vanadium (V), % | 0.1 to 0.3 | |
| 0 |