Hardened SAE-AISI H25 vs. Hardened SAE-AISI M3 Class 2
Both hardened SAE-AISI H25 and hardened SAE-AISI M3 class 2 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 H25 and the bottom bar is hardened SAE-AISI M3 class 2.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 200 | |
| 200 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Rockwell C Hardness | 50 | |
| 68 |
| Shear Modulus, GPa | 79 | |
| 77 |
| Tensile Strength: Ultimate (UTS), MPa | 1620 | |
| 2210 |
Thermal Properties
| Latent Heat of Fusion, J/g | 250 | |
| 260 |
| Melting Completion (Liquidus), °C | 1750 | |
| 1620 |
| Melting Onset (Solidus), °C | 1700 | |
| 1570 |
| Specific Heat Capacity, J/kg-K | 420 | |
| 440 |
| Thermal Conductivity, W/m-K | 26 | |
| 26 |
| Thermal Expansion, µm/m-K | 12 | |
| 12 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 38 | |
| 25 |
| Density, g/cm3 | 9.1 | |
| 8.3 |
| Embodied Carbon, kg CO2/kg material | 6.2 | |
| 12 |
| Embodied Energy, MJ/kg | 93 | |
| 180 |
| Embodied Water, L/kg | 83 | |
| 110 |
Common Calculations
| PREN (Pitting Resistance) | 29 | |
| 33 |
| Stiffness to Weight: Axial, points | 12 | |
| 13 |
| Stiffness to Weight: Bending, points | 22 | |
| 23 |
| Strength to Weight: Axial, points | 50 | |
| 74 |
| Strength to Weight: Bending, points | 34 | |
| 45 |
| Thermal Diffusivity, mm2/s | 6.7 | |
| 7.2 |
| Thermal Shock Resistance, points | 49 | |
| 69 |
Alloy Composition
| Carbon (C), % | 0.22 to 0.32 | |
| 1.2 to 1.3 |
| Chromium (Cr), % | 3.8 to 4.5 | |
| 3.8 to 4.5 |
| Copper (Cu), % | 0 to 0.25 | |
| 0 to 0.25 |
| Iron (Fe), % | 77.2 to 81.3 | |
| 75.8 to 82.3 |
| Manganese (Mn), % | 0.15 to 0.4 | |
| 0.15 to 0.4 |
| Molybdenum (Mo), % | 0 | |
| 4.8 to 6.5 |
| 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 0.4 | |
| 0.2 to 0.45 |
| Sulfur (S), % | 0 to 0.030 | |
| 0 to 0.030 |
| Tungsten (W), % | 14 to 16 | |
| 5.0 to 6.8 |
| Vanadium (V), % | 0.4 to 0.6 | |
| 2.8 to 3.8 |