SAE-AISI 8640 Steel vs. SAE-AISI S4 Steel
Both SAE-AISI 8640 steel and SAE-AISI S4 steel are iron alloys. They have a very high 98% of their average alloy composition in common. There are 23 material properties with values for both materials. Properties with values for just one material (8, in this case) are not shown.
For each property being compared, the top bar is SAE-AISI 8640 steel and the bottom bar is SAE-AISI S4 steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 190 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Shear Modulus, GPa | 73 | |
| 72 |
| Tensile Strength: Ultimate (UTS), MPa | 570 | |
| 670 to 2140 |
Thermal Properties
| Latent Heat of Fusion, J/g | 250 | |
| 280 |
| Melting Completion (Liquidus), °C | 1460 | |
| 1430 |
| Melting Onset (Solidus), °C | 1420 | |
| 1390 |
| Specific Heat Capacity, J/kg-K | 470 | |
| 480 |
| Thermal Conductivity, W/m-K | 39 | |
| 44 |
| Thermal Expansion, µm/m-K | 13 | |
| 13 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 7.3 | |
| 7.4 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 8.4 | |
| 8.7 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 2.6 | |
| 2.2 |
| Density, g/cm3 | 7.8 | |
| 7.7 |
| Embodied Carbon, kg CO2/kg material | 1.5 | |
| 2.0 |
| Embodied Energy, MJ/kg | 20 | |
| 29 |
| Embodied Water, L/kg | 50 | |
| 48 |
Common Calculations
| Stiffness to Weight: Axial, points | 13 | |
| 13 |
| Stiffness to Weight: Bending, points | 24 | |
| 25 |
| Strength to Weight: Axial, points | 20 | |
| 24 to 77 |
| Strength to Weight: Bending, points | 20 | |
| 22 to 48 |
| Thermal Diffusivity, mm2/s | 10 | |
| 12 |
| Thermal Shock Resistance, points | 17 | |
| 20 to 65 |
Alloy Composition
| Carbon (C), % | 0.38 to 0.43 | |
| 0.5 to 0.65 |
| Chromium (Cr), % | 0.4 to 0.6 | |
| 0.1 to 0.5 |
| Iron (Fe), % | 96.6 to 97.8 | |
| 95.2 to 96.9 |
| Manganese (Mn), % | 0.75 to 1.0 | |
| 0.6 to 1.0 |
| Molybdenum (Mo), % | 0.15 to 0.25 | |
| 0 |
| Nickel (Ni), % | 0.4 to 0.7 | |
| 0 |
| Phosphorus (P), % | 0 to 0.035 | |
| 0 to 0.030 |
| Silicon (Si), % | 0.15 to 0.35 | |
| 1.8 to 2.3 |
| Sulfur (S), % | 0 to 0.040 | |
| 0 to 0.030 |
| Vanadium (V), % | 0 | |
| 0.15 to 0.35 |