Hardened SAE-AISI A4 vs. Hardened SAE-AISI A6
Both hardened SAE-AISI A4 and hardened SAE-AISI A6 are iron alloys. Both are furnished in the hardened (H) condition. Their average alloy composition is basically identical.
For each property being compared, the top bar is hardened SAE-AISI A4 and the bottom bar is hardened SAE-AISI A6.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 190 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Rockwell C Hardness | 63 | |
| 62 |
| Shear Modulus, GPa | 73 | |
| 73 |
| Tensile Strength: Ultimate (UTS), MPa | 2050 | |
| 1990 |
Thermal Properties
| Latent Heat of Fusion, J/g | 250 | |
| 250 |
| Melting Completion (Liquidus), °C | 1450 | |
| 1460 |
| Melting Onset (Solidus), °C | 1410 | |
| 1410 |
| Specific Heat Capacity, J/kg-K | 470 | |
| 470 |
| Thermal Conductivity, W/m-K | 40 | |
| 41 |
| Thermal Expansion, µm/m-K | 12 | |
| 12 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 7.4 | |
| 7.5 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 8.6 | |
| 8.7 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 3.9 | |
| 3.7 |
| Density, g/cm3 | 7.8 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 1.8 | |
| 1.8 |
| Embodied Energy, MJ/kg | 24 | |
| 24 |
| Embodied Water, L/kg | 59 | |
| 57 |
Common Calculations
| PREN (Pitting Resistance) | 5.3 | |
| 4.8 |
| Stiffness to Weight: Axial, points | 13 | |
| 13 |
| Stiffness to Weight: Bending, points | 24 | |
| 24 |
| Strength to Weight: Axial, points | 73 | |
| 71 |
| Strength to Weight: Bending, points | 46 | |
| 45 |
| Thermal Diffusivity, mm2/s | 11 | |
| 11 |
| Thermal Shock Resistance, points | 67 | |
| 65 |
Alloy Composition
| Carbon (C), % | 1.0 to 1.1 | |
| 0.65 to 0.75 |
| Chromium (Cr), % | 0.9 to 2.2 | |
| 0.9 to 1.2 |
| Copper (Cu), % | 0 to 0.25 | |
| 0 to 0.25 |
| Iron (Fe), % | 92 to 95.5 | |
| 93 to 95.8 |
| Manganese (Mn), % | 1.8 to 2.2 | |
| 1.8 to 2.5 |
| Molybdenum (Mo), % | 0.9 to 1.4 | |
| 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 to 0.5 | |
| 0 to 0.5 |
| Sulfur (S), % | 0 to 0.030 | |
| 0 to 0.030 |