Hardened SAE-AISI H42 vs. Hardened SAE-AISI M30
Both hardened SAE-AISI H42 and hardened SAE-AISI M30 are iron alloys. Both are furnished in the hardened (H) condition. They have a moderately high 91% of their average alloy composition in common.
For each property being compared, the top bar is hardened SAE-AISI H42 and the bottom bar is hardened SAE-AISI M30.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 200 | |
| 200 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Rockwell C Hardness | 61 | |
| 67 |
| Shear Modulus, GPa | 77 | |
| 78 |
| Tensile Strength: Ultimate (UTS), MPa | 1980 | |
| 2170 |
Thermal Properties
| Latent Heat of Fusion, J/g | 260 | |
| 270 |
| Melting Completion (Liquidus), °C | 1620 | |
| 1550 |
| Melting Onset (Solidus), °C | 1570 | |
| 1500 |
| Specific Heat Capacity, J/kg-K | 440 | |
| 450 |
| Thermal Conductivity, W/m-K | 24 | |
| 24 |
| Thermal Expansion, µm/m-K | 12 | |
| 12 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 24 | |
| 26 |
| Density, g/cm3 | 8.4 | |
| 8.2 |
| Embodied Carbon, kg CO2/kg material | 8.8 | |
| 7.2 |
| Embodied Energy, MJ/kg | 130 | |
| 100 |
| Embodied Water, L/kg | 98 | |
| 120 |
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 | 65 | |
| 74 |
| Strength to Weight: Bending, points | 42 | |
| 46 |
| Thermal Diffusivity, mm2/s | 6.5 | |
| 6.6 |
| Thermal Shock Resistance, points | 57 | |
| 67 |
Alloy Composition
| Carbon (C), % | 0.55 to 0.7 | |
| 0.75 to 0.85 |
| Chromium (Cr), % | 3.8 to 4.5 | |
| 3.5 to 4.3 |
| Cobalt (Co), % | 0 | |
| 4.5 to 5.5 |
| Copper (Cu), % | 0 to 0.25 | |
| 0 to 0.25 |
| Iron (Fe), % | 79.3 to 83.8 | |
| 75.2 to 80.9 |
| Manganese (Mn), % | 0.15 to 0.4 | |
| 0.15 to 0.4 |
| Molybdenum (Mo), % | 4.5 to 5.5 | |
| 7.8 to 9.0 |
| Nickel (Ni), % | 0 to 0.3 | |
| 0 to 0.3 |
| Phosphorus (P), % | 0 to 0.030 | |
| 0 to 0.030 |
| Silicon (Si), % | 0 | |
| 0.2 to 0.45 |
| Sulfur (S), % | 0 to 0.030 | |
| 0 to 0.030 |
| Tungsten (W), % | 5.5 to 6.8 | |
| 1.3 to 2.3 |
| Vanadium (V), % | 1.8 to 2.2 | |
| 1.0 to 1.4 |