S45500 Stainless Steel vs. R30021 Cobalt
S45500 stainless steel belongs to the iron alloys classification, while R30021 cobalt belongs to the cobalt alloys. There are 23 material properties with values for both materials. Properties with values for just one material (13, in this case) are not shown.
For each property being compared, the top bar is S45500 stainless steel and the bottom bar is R30021 cobalt.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 220 |
| Elongation at Break, % | 3.4 to 11 | |
| 9.0 |
| Fatigue Strength, MPa | 570 to 890 | |
| 250 |
| Poisson's Ratio | 0.28 | |
| 0.29 |
| Rockwell C Hardness | 32 to 54 | |
| 32 |
| Shear Modulus, GPa | 75 | |
| 86 |
| Tensile Strength: Ultimate (UTS), MPa | 1370 to 1850 | |
| 700 |
| Tensile Strength: Yield (Proof), MPa | 1240 to 1700 | |
| 500 |
Thermal Properties
| Latent Heat of Fusion, J/g | 270 | |
| 330 |
| Melting Completion (Liquidus), °C | 1440 | |
| 1350 |
| Melting Onset (Solidus), °C | 1400 | |
| 1190 |
| Specific Heat Capacity, J/kg-K | 470 | |
| 450 |
| Thermal Expansion, µm/m-K | 11 | |
| 11 |
Otherwise Unclassified Properties
| Density, g/cm3 | 7.9 | |
| 8.4 |
| Embodied Carbon, kg CO2/kg material | 3.8 | |
| 8.0 |
| Embodied Energy, MJ/kg | 57 | |
| 110 |
| Embodied Water, L/kg | 120 | |
| 520 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 45 to 190 | |
| 57 |
| Stiffness to Weight: Axial, points | 14 | |
| 15 |
| Stiffness to Weight: Bending, points | 24 | |
| 24 |
| Strength to Weight: Axial, points | 48 to 65 | |
| 23 |
| Strength to Weight: Bending, points | 35 to 42 | |
| 21 |
| Thermal Shock Resistance, points | 48 to 64 | |
| 21 |
Alloy Composition
| Carbon (C), % | 0 to 0.050 | |
| 0.2 to 0.35 |
| Chromium (Cr), % | 11 to 12.5 | |
| 26 to 29 |
| Cobalt (Co), % | 0 | |
| 61.7 to 67.3 |
| Copper (Cu), % | 1.5 to 2.5 | |
| 0 |
| Iron (Fe), % | 71.5 to 79.2 | |
| 0 to 3.0 |
| Manganese (Mn), % | 0 to 0.5 | |
| 0 |
| Molybdenum (Mo), % | 0 to 0.5 | |
| 4.5 to 6.0 |
| Nickel (Ni), % | 7.5 to 9.5 | |
| 2.0 to 3.0 |
| Niobium (Nb), % | 0 to 0.5 | |
| 0 |
| Phosphorus (P), % | 0 to 0.040 | |
| 0 |
| Silicon (Si), % | 0 to 0.5 | |
| 0 to 1.5 |
| Sulfur (S), % | 0 to 0.030 | |
| 0 |
| Tantalum (Ta), % | 0 to 0.5 | |
| 0 |
| Titanium (Ti), % | 0.8 to 1.4 | |
| 0 |