S21603 Stainless Steel vs. R30605 Cobalt
S21603 stainless steel belongs to the iron alloys classification, while R30605 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 21 material properties with values for both materials. Properties with values for just one material (14, in this case) are not shown.
For each property being compared, the top bar is S21603 stainless steel and the bottom bar is R30605 cobalt.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 200 | |
| 210 |
| Elongation at Break, % | 45 | |
| 34 |
| Fatigue Strength, MPa | 360 | |
| 260 to 590 |
| Poisson's Ratio | 0.28 | |
| 0.29 |
| Shear Modulus, GPa | 79 | |
| 81 |
| Tensile Strength: Ultimate (UTS), MPa | 690 | |
| 1130 to 1900 |
| Tensile Strength: Yield (Proof), MPa | 390 | |
| 470 to 1600 |
Thermal Properties
| Latent Heat of Fusion, J/g | 290 | |
| 290 |
| Melting Completion (Liquidus), °C | 1420 | |
| 1410 |
| Melting Onset (Solidus), °C | 1380 | |
| 1330 |
| Specific Heat Capacity, J/kg-K | 480 | |
| 410 |
| Thermal Expansion, µm/m-K | 17 | |
| 12 |
Otherwise Unclassified Properties
| Density, g/cm3 | 7.7 | |
| 9.6 |
| Embodied Carbon, kg CO2/kg material | 3.6 | |
| 9.8 |
| Embodied Energy, MJ/kg | 50 | |
| 140 |
| Embodied Water, L/kg | 160 | |
| 450 |
Common Calculations
| Stiffness to Weight: Axial, points | 14 | |
| 12 |
| Stiffness to Weight: Bending, points | 25 | |
| 21 |
| Strength to Weight: Axial, points | 25 | |
| 33 to 55 |
| Strength to Weight: Bending, points | 22 | |
| 25 to 36 |
| Thermal Shock Resistance, points | 15 | |
| 31 to 52 |
Alloy Composition
| Carbon (C), % | 0 to 0.030 | |
| 0.050 to 0.15 |
| Chromium (Cr), % | 17.5 to 22 | |
| 19 to 21 |
| Cobalt (Co), % | 0 | |
| 46.4 to 57 |
| Iron (Fe), % | 57.6 to 67.8 | |
| 0 to 3.0 |
| Manganese (Mn), % | 7.5 to 9.0 | |
| 1.0 to 2.0 |
| Molybdenum (Mo), % | 2.0 to 3.0 | |
| 0 |
| Nickel (Ni), % | 5.0 to 7.0 | |
| 9.0 to 11 |
| Nitrogen (N), % | 0.25 to 0.5 | |
| 0 |
| Phosphorus (P), % | 0 to 0.045 | |
| 0 to 0.040 |
| Silicon (Si), % | 0 to 0.75 | |
| 0 to 0.4 |
| Sulfur (S), % | 0 to 0.030 | |
| 0 to 0.030 |
| Tungsten (W), % | 0 | |
| 14 to 16 |