AISI 420 Stainless Steel vs. R30021 Cobalt
AISI 420 stainless steel belongs to the iron alloys classification, while R30021 cobalt belongs to the cobalt alloys. There are 27 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 AISI 420 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, % | 8.0 to 15 | |
| 9.0 |
| Fatigue Strength, MPa | 220 to 670 | |
| 250 |
| Poisson's Ratio | 0.28 | |
| 0.29 |
| Shear Modulus, GPa | 76 | |
| 86 |
| Tensile Strength: Ultimate (UTS), MPa | 690 to 1720 | |
| 700 |
| Tensile Strength: Yield (Proof), MPa | 380 to 1310 | |
| 500 |
Thermal Properties
| Latent Heat of Fusion, J/g | 280 | |
| 330 |
| Melting Completion (Liquidus), °C | 1510 | |
| 1350 |
| Melting Onset (Solidus), °C | 1450 | |
| 1190 |
| Specific Heat Capacity, J/kg-K | 480 | |
| 450 |
| Thermal Conductivity, W/m-K | 27 | |
| 15 |
| Thermal Expansion, µm/m-K | 10 | |
| 11 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 3.0 | |
| 1.9 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 3.5 | |
| 2.1 |
Otherwise Unclassified Properties
| Density, g/cm3 | 7.7 | |
| 8.4 |
| Embodied Carbon, kg CO2/kg material | 2.0 | |
| 8.0 |
| Embodied Energy, MJ/kg | 28 | |
| 110 |
| Embodied Water, L/kg | 100 | |
| 520 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 88 to 130 | |
| 57 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 380 to 4410 | |
| 570 |
| Stiffness to Weight: Axial, points | 14 | |
| 15 |
| Stiffness to Weight: Bending, points | 25 | |
| 24 |
| Strength to Weight: Axial, points | 25 to 62 | |
| 23 |
| Strength to Weight: Bending, points | 22 to 41 | |
| 21 |
| Thermal Diffusivity, mm2/s | 7.3 | |
| 3.8 |
| Thermal Shock Resistance, points | 25 to 62 | |
| 21 |
Alloy Composition
| Carbon (C), % | 0.15 to 0.4 | |
| 0.2 to 0.35 |
| Chromium (Cr), % | 12 to 14 | |
| 26 to 29 |
| Cobalt (Co), % | 0 | |
| 61.7 to 67.3 |
| Iron (Fe), % | 82.3 to 87.9 | |
| 0 to 3.0 |
| Manganese (Mn), % | 0 to 1.0 | |
| 0 |
| Molybdenum (Mo), % | 0 to 0.5 | |
| 4.5 to 6.0 |
| Nickel (Ni), % | 0 to 0.75 | |
| 2.0 to 3.0 |
| Phosphorus (P), % | 0 to 0.040 | |
| 0 |
| Silicon (Si), % | 0 to 1.0 | |
| 0 to 1.5 |
| Sulfur (S), % | 0 to 0.030 | |
| 0 |