AISI 440A Stainless Steel vs. G-CoCr28 Cobalt
AISI 440A stainless steel belongs to the iron alloys classification, while G-CoCr28 cobalt belongs to the cobalt alloys. They have a modest 36% of their average alloy composition in common, which, by itself, doesn't mean much. There are 26 material properties with values for both materials. Properties with values for just one material (6, in this case) are not shown.
For each property being compared, the top bar is AISI 440A stainless steel and the bottom bar is G-CoCr28 cobalt.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 200 | |
| 210 |
| Elongation at Break, % | 5.0 to 20 | |
| 6.7 |
| Fatigue Strength, MPa | 270 to 790 | |
| 130 |
| Poisson's Ratio | 0.28 | |
| 0.28 |
| Shear Modulus, GPa | 77 | |
| 83 |
| Tensile Strength: Ultimate (UTS), MPa | 730 to 1790 | |
| 560 |
| Tensile Strength: Yield (Proof), MPa | 420 to 1650 | |
| 260 |
Thermal Properties
| Latent Heat of Fusion, J/g | 280 | |
| 320 |
| Maximum Temperature: Mechanical, °C | 760 | |
| 1200 |
| Melting Completion (Liquidus), °C | 1480 | |
| 1330 |
| Melting Onset (Solidus), °C | 1370 | |
| 1270 |
| Specific Heat Capacity, J/kg-K | 480 | |
| 470 |
| Thermal Conductivity, W/m-K | 23 | |
| 8.5 |
| Thermal Expansion, µm/m-K | 10 | |
| 14 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 9.0 | |
| 100 |
| Density, g/cm3 | 7.7 | |
| 8.1 |
| Embodied Carbon, kg CO2/kg material | 2.2 | |
| 6.2 |
| Embodied Energy, MJ/kg | 31 | |
| 84 |
| Embodied Water, L/kg | 120 | |
| 440 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 87 to 120 | |
| 31 |
| Stiffness to Weight: Axial, points | 14 | |
| 15 |
| Stiffness to Weight: Bending, points | 25 | |
| 24 |
| Strength to Weight: Axial, points | 26 to 65 | |
| 19 |
| Strength to Weight: Bending, points | 23 to 43 | |
| 19 |
| Thermal Diffusivity, mm2/s | 6.2 | |
| 2.2 |
| Thermal Shock Resistance, points | 26 to 65 | |
| 14 |
Alloy Composition
| Carbon (C), % | 0.6 to 0.75 | |
| 0.050 to 0.25 |
| Chromium (Cr), % | 16 to 18 | |
| 27 to 30 |
| Cobalt (Co), % | 0 | |
| 48 to 52 |
| Iron (Fe), % | 78.4 to 83.4 | |
| 9.7 to 24.5 |
| Manganese (Mn), % | 0 to 1.0 | |
| 0 to 1.5 |
| Molybdenum (Mo), % | 0 to 0.75 | |
| 0 to 0.5 |
| Nickel (Ni), % | 0 | |
| 0 to 4.0 |
| Niobium (Nb), % | 0 | |
| 0 to 0.5 |
| Phosphorus (P), % | 0 to 0.040 | |
| 0 to 0.040 |
| Silicon (Si), % | 0 to 1.0 | |
| 0.5 to 1.5 |
| Sulfur (S), % | 0 to 0.015 | |
| 0 to 0.030 |