SAE-AISI M42 Steel vs. SAE-AISI A7 Steel
Both SAE-AISI M42 steel and SAE-AISI A7 steel are iron alloys. They have 88% of their average alloy composition in common.
For each property being compared, the top bar is SAE-AISI M42 steel and the bottom bar is SAE-AISI A7 steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 200 | |
| 190 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Shear Modulus, GPa | 78 | |
| 72 |
| Tensile Strength: Ultimate (UTS), MPa | 810 to 2310 | |
| 800 to 2150 |
Thermal Properties
| Latent Heat of Fusion, J/g | 270 | |
| 260 |
| Melting Completion (Liquidus), °C | 1540 | |
| 1470 |
| Melting Onset (Solidus), °C | 1490 | |
| 1430 |
| Specific Heat Capacity, J/kg-K | 450 | |
| 470 |
| Thermal Conductivity, W/m-K | 20 | |
| 37 |
| Thermal Expansion, µm/m-K | 12 | |
| 12 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 30 | |
| 10 |
| Density, g/cm3 | 8.2 | |
| 7.7 |
| Embodied Carbon, kg CO2/kg material | 7.4 | |
| 13 |
| Embodied Energy, MJ/kg | 100 | |
| 200 |
| Embodied Water, L/kg | 140 | |
| 100 |
Common Calculations
| PREN (Pitting Resistance) | 38 | |
| 11 |
| Stiffness to Weight: Axial, points | 14 | |
| 13 |
| Stiffness to Weight: Bending, points | 24 | |
| 25 |
| Strength to Weight: Axial, points | 28 to 79 | |
| 29 to 77 |
| Strength to Weight: Bending, points | 24 to 48 | |
| 25 to 48 |
| Thermal Diffusivity, mm2/s | 5.4 | |
| 10 |
| Thermal Shock Resistance, points | 25 to 71 | |
| 27 to 72 |
Alloy Composition
| Carbon (C), % | 1.1 to 1.2 | |
| 2.0 to 2.9 |
| Chromium (Cr), % | 3.5 to 4.3 | |
| 5.0 to 5.8 |
| Cobalt (Co), % | 7.8 to 8.8 | |
| 0 |
| Copper (Cu), % | 0 to 0.25 | |
| 0 to 0.25 |
| Iron (Fe), % | 76.3 to 81 | |
| 81.4 to 87.7 |
| Manganese (Mn), % | 0.15 to 0.4 | |
| 0 to 0.8 |
| Molybdenum (Mo), % | 9.0 to 10 | |
| 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), % | 0.15 to 0.65 | |
| 0 to 0.5 |
| Sulfur (S), % | 0 to 0.030 | |
| 0 to 0.030 |
| Tungsten (W), % | 1.2 to 1.9 | |
| 0.5 to 1.5 |
| Vanadium (V), % | 1.0 to 1.4 | |
| 3.9 to 5.2 |