SAE-AISI 1055 Steel vs. R31537 Cobalt
SAE-AISI 1055 steel belongs to the iron alloys classification, while R31537 cobalt belongs to the cobalt alloys. There are 28 material properties with values for both materials. Properties with values for just one material (5, in this case) are not shown.
For each property being compared, the top bar is SAE-AISI 1055 steel and the bottom bar is R31537 cobalt.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 220 |
| Elongation at Break, % | 11 to 14 | |
| 14 to 23 |
| Fatigue Strength, MPa | 260 to 390 | |
| 310 to 480 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Reduction in Area, % | 34 to 45 | |
| 13 to 23 |
| Shear Modulus, GPa | 72 | |
| 87 |
| Tensile Strength: Ultimate (UTS), MPa | 730 to 750 | |
| 1000 to 1340 |
| Tensile Strength: Yield (Proof), MPa | 400 to 630 | |
| 590 to 940 |
Thermal Properties
| Latent Heat of Fusion, J/g | 250 | |
| 320 |
| Melting Completion (Liquidus), °C | 1460 | |
| 1360 |
| Melting Onset (Solidus), °C | 1420 | |
| 1290 |
| Specific Heat Capacity, J/kg-K | 470 | |
| 450 |
| Thermal Conductivity, W/m-K | 51 | |
| 13 |
| Thermal Expansion, µm/m-K | 12 | |
| 13 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 11 | |
| 2.0 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 12 | |
| 2.1 |
Otherwise Unclassified Properties
| Density, g/cm3 | 7.8 | |
| 8.4 |
| Embodied Carbon, kg CO2/kg material | 1.4 | |
| 8.1 |
| Embodied Energy, MJ/kg | 18 | |
| 110 |
| Embodied Water, L/kg | 46 | |
| 530 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 80 to 85 | |
| 140 to 200 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 440 to 1070 | |
| 780 to 1990 |
| Stiffness to Weight: Axial, points | 13 | |
| 15 |
| Stiffness to Weight: Bending, points | 24 | |
| 24 |
| Strength to Weight: Axial, points | 26 | |
| 33 to 44 |
| Strength to Weight: Bending, points | 23 | |
| 26 to 32 |
| Thermal Diffusivity, mm2/s | 14 | |
| 3.4 |
| Thermal Shock Resistance, points | 23 to 24 | |
| 24 to 32 |
Alloy Composition
| Carbon (C), % | 0.5 to 0.6 | |
| 0 to 0.14 |
| Chromium (Cr), % | 0 | |
| 26 to 30 |
| Cobalt (Co), % | 0 | |
| 58.9 to 69 |
| Iron (Fe), % | 98.4 to 98.9 | |
| 0 to 0.75 |
| Manganese (Mn), % | 0.6 to 0.9 | |
| 0 to 1.0 |
| Molybdenum (Mo), % | 0 | |
| 5.0 to 7.0 |
| Nickel (Ni), % | 0 | |
| 0 to 1.0 |
| Nitrogen (N), % | 0 | |
| 0 to 0.25 |
| Phosphorus (P), % | 0 to 0.040 | |
| 0 |
| Silicon (Si), % | 0 | |
| 0 to 1.0 |
| Sulfur (S), % | 0 to 0.050 | |
| 0 |