SAE-AISI A8 Steel vs. SAE-AISI A4 Steel
Both SAE-AISI A8 steel and SAE-AISI A4 steel are iron alloys. They have a moderately high 94% of their average alloy composition in common.
For each property being compared, the top bar is SAE-AISI A8 steel and the bottom bar is SAE-AISI A4 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 | 74 | |
| 73 |
| Tensile Strength: Ultimate (UTS), MPa | 700 to 1920 | |
| 710 to 2050 |
Thermal Properties
| Latent Heat of Fusion, J/g | 270 | |
| 250 |
| Melting Completion (Liquidus), °C | 1480 | |
| 1450 |
| Melting Onset (Solidus), °C | 1430 | |
| 1410 |
| Specific Heat Capacity, J/kg-K | 470 | |
| 470 |
| Thermal Conductivity, W/m-K | 37 | |
| 40 |
| Thermal Expansion, µm/m-K | 12 | |
| 12 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 8.3 | |
| 7.4 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 9.5 | |
| 8.6 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 8.5 | |
| 3.9 |
| Density, g/cm3 | 7.9 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 2.3 | |
| 1.8 |
| Embodied Energy, MJ/kg | 31 | |
| 24 |
| Embodied Water, L/kg | 73 | |
| 59 |
Common Calculations
| PREN (Pitting Resistance) | 12 | |
| 5.3 |
| Stiffness to Weight: Axial, points | 14 | |
| 13 |
| Stiffness to Weight: Bending, points | 24 | |
| 24 |
| Strength to Weight: Axial, points | 25 to 68 | |
| 25 to 73 |
| Strength to Weight: Bending, points | 22 to 44 | |
| 23 to 46 |
| Thermal Diffusivity, mm2/s | 9.9 | |
| 11 |
| Thermal Shock Resistance, points | 22 to 62 | |
| 23 to 67 |
Alloy Composition
| Carbon (C), % | 0.5 to 0.6 | |
| 1.0 to 1.1 |
| Chromium (Cr), % | 4.8 to 5.5 | |
| 0.9 to 2.2 |
| Copper (Cu), % | 0 to 0.25 | |
| 0 to 0.25 |
| Iron (Fe), % | 88.5 to 91.9 | |
| 92 to 95.5 |
| Manganese (Mn), % | 0 to 0.5 | |
| 1.8 to 2.2 |
| Molybdenum (Mo), % | 1.2 to 1.7 | |
| 0.9 to 1.4 |
| Nickel (Ni), % | 0 to 0.3 | |
| 0 to 0.3 |
| Phosphorus (P), % | 0 to 0.030 | |
| 0 to 0.030 |
| Silicon (Si), % | 0.75 to 1.1 | |
| 0 to 0.5 |
| Sulfur (S), % | 0 to 0.030 | |
| 0 to 0.030 |
| Tungsten (W), % | 1.0 to 1.5 | |
| 0 |