R30021 Cobalt vs. S15500 Stainless Steel
R30021 cobalt belongs to the cobalt alloys classification, while S15500 stainless steel belongs to the iron alloys. There are 28 material properties with values for both materials. Properties with values for just one material (9, in this case) are not shown.
For each property being compared, the top bar is R30021 cobalt and the bottom bar is S15500 stainless steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 220 | |
| 190 |
| Elongation at Break, % | 9.0 | |
| 6.8 to 16 |
| Fatigue Strength, MPa | 250 | |
| 350 to 650 |
| Poisson's Ratio | 0.29 | |
| 0.28 |
| Rockwell C Hardness | 32 | |
| 27 to 46 |
| Shear Modulus, GPa | 86 | |
| 75 |
| Tensile Strength: Ultimate (UTS), MPa | 700 | |
| 890 to 1490 |
| Tensile Strength: Yield (Proof), MPa | 500 | |
| 590 to 1310 |
Thermal Properties
| Latent Heat of Fusion, J/g | 330 | |
| 280 |
| Melting Completion (Liquidus), °C | 1350 | |
| 1430 |
| Melting Onset (Solidus), °C | 1190 | |
| 1380 |
| Specific Heat Capacity, J/kg-K | 450 | |
| 480 |
| Thermal Conductivity, W/m-K | 15 | |
| 17 |
| Thermal Expansion, µm/m-K | 11 | |
| 11 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 1.9 | |
| 2.2 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 2.1 | |
| 2.5 |
Otherwise Unclassified Properties
| Density, g/cm3 | 8.4 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 8.0 | |
| 2.7 |
| Embodied Energy, MJ/kg | 110 | |
| 39 |
| Embodied Water, L/kg | 520 | |
| 130 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 57 | |
| 98 to 120 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 570 | |
| 890 to 4460 |
| Stiffness to Weight: Axial, points | 15 | |
| 14 |
| Stiffness to Weight: Bending, points | 24 | |
| 25 |
| Strength to Weight: Axial, points | 23 | |
| 32 to 53 |
| Strength to Weight: Bending, points | 21 | |
| 26 to 37 |
| Thermal Diffusivity, mm2/s | 3.8 | |
| 4.6 |
| Thermal Shock Resistance, points | 21 | |
| 30 to 50 |
Alloy Composition
| Carbon (C), % | 0.2 to 0.35 | |
| 0 to 0.070 |
| Chromium (Cr), % | 26 to 29 | |
| 14 to 15.5 |
| Cobalt (Co), % | 61.7 to 67.3 | |
| 0 |
| Copper (Cu), % | 0 | |
| 2.5 to 4.5 |
| Iron (Fe), % | 0 to 3.0 | |
| 71.9 to 79.9 |
| Manganese (Mn), % | 0 | |
| 0 to 1.0 |
| Molybdenum (Mo), % | 4.5 to 6.0 | |
| 0 |
| Nickel (Ni), % | 2.0 to 3.0 | |
| 3.5 to 5.5 |
| Niobium (Nb), % | 0 | |
| 0.15 to 0.45 |
| Phosphorus (P), % | 0 | |
| 0 to 0.040 |
| Silicon (Si), % | 0 to 1.5 | |
| 0 to 1.0 |
| Sulfur (S), % | 0 | |
| 0 to 0.030 |