Hardened SAE-AISI M2 vs. Hardened SAE-AISI M7
Both hardened SAE-AISI M2 and hardened SAE-AISI M7 are iron alloys. Both are furnished in the hardened (H) condition. They have a very high 95% of their average alloy composition in common.
For each property being compared, the top bar is hardened SAE-AISI M2 and the bottom bar is hardened SAE-AISI M7.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 200 | |
| 200 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Rockwell C Hardness | 66 | |
| 68 |
| Shear Modulus, GPa | 77 | |
| 77 |
| Tensile Strength: Ultimate (UTS), MPa | 2150 | |
| 2210 |
Thermal Properties
| Latent Heat of Fusion, J/g | 260 | |
| 270 |
| Melting Completion (Liquidus), °C | 1610 | |
| 1560 |
| Melting Onset (Solidus), °C | 1570 | |
| 1510 |
| Specific Heat Capacity, J/kg-K | 440 | |
| 450 |
| Thermal Conductivity, W/m-K | 22 | |
| 28 |
| Thermal Expansion, µm/m-K | 10 | |
| 12 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 24 | |
| 18 |
| Density, g/cm3 | 8.4 | |
| 8.1 |
| Embodied Carbon, kg CO2/kg material | 8.8 | |
| 8.9 |
| Embodied Energy, MJ/kg | 130 | |
| 130 |
| Embodied Water, L/kg | 98 | |
| 100 |
Common Calculations
| PREN (Pitting Resistance) | 31 | |
| 35 |
| Stiffness to Weight: Axial, points | 13 | |
| 14 |
| Stiffness to Weight: Bending, points | 23 | |
| 24 |
| Strength to Weight: Axial, points | 71 | |
| 76 |
| Strength to Weight: Bending, points | 44 | |
| 47 |
| Thermal Diffusivity, mm2/s | 5.9 | |
| 7.8 |
| Thermal Shock Resistance, points | 76 | |
| 69 |
Alloy Composition
| Carbon (C), % | 0.78 to 1.1 | |
| 1.0 to 1.1 |
| Chromium (Cr), % | 3.8 to 4.5 | |
| 3.5 to 4.0 |
| Copper (Cu), % | 0 to 0.25 | |
| 0 to 0.25 |
| Iron (Fe), % | 78.5 to 83.4 | |
| 79.8 to 83.8 |
| Manganese (Mn), % | 0.15 to 0.4 | |
| 0.15 to 0.4 |
| Molybdenum (Mo), % | 4.5 to 5.5 | |
| 8.2 to 9.2 |
| Nickel (Ni), % | 0 to 0.3 | |
| 0 to 0.3 |
| Phosphorus (P), % | 0 to 0.030 | |
| 0 to 0.030 |
| Silicon (Si), % | 0.2 to 0.45 | |
| 0.2 to 0.55 |
| Sulfur (S), % | 0 to 0.030 | |
| 0 to 0.030 |
| Tungsten (W), % | 5.5 to 6.8 | |
| 1.4 to 2.1 |
| Vanadium (V), % | 1.8 to 2.2 | |
| 1.8 to 2.3 |