ASTM A387 Grade 91 Class 2 vs. SAE-AISI M3 Class 2 Steel
Both ASTM A387 grade 91 class 2 and SAE-AISI M3 class 2 steel are iron alloys. They have 85% of their average alloy composition in common. There are 22 material properties with values for both materials. Properties with values for just one material (10, in this case) are not shown.
For each property being compared, the top bar is ASTM A387 grade 91 class 2 and the bottom bar is SAE-AISI M3 class 2 steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 200 |
| Poisson's Ratio | 0.28 | |
| 0.29 |
| Shear Modulus, GPa | 75 | |
| 77 |
| Tensile Strength: Ultimate (UTS), MPa | 670 | |
| 770 to 2210 |
Thermal Properties
| Latent Heat of Fusion, J/g | 270 | |
| 260 |
| Melting Completion (Liquidus), °C | 1460 | |
| 1620 |
| Melting Onset (Solidus), °C | 1420 | |
| 1570 |
| Specific Heat Capacity, J/kg-K | 470 | |
| 440 |
| Thermal Conductivity, W/m-K | 26 | |
| 26 |
| Thermal Expansion, µm/m-K | 13 | |
| 12 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 7.0 | |
| 25 |
| Density, g/cm3 | 7.8 | |
| 8.3 |
| Embodied Carbon, kg CO2/kg material | 2.6 | |
| 12 |
| Embodied Energy, MJ/kg | 37 | |
| 180 |
| Embodied Water, L/kg | 88 | |
| 110 |
Common Calculations
| PREN (Pitting Resistance) | 13 | |
| 33 |
| Stiffness to Weight: Axial, points | 14 | |
| 13 |
| Stiffness to Weight: Bending, points | 25 | |
| 23 |
| Strength to Weight: Axial, points | 24 | |
| 26 to 74 |
| Strength to Weight: Bending, points | 22 | |
| 22 to 45 |
| Thermal Diffusivity, mm2/s | 6.9 | |
| 7.2 |
| Thermal Shock Resistance, points | 19 | |
| 24 to 69 |
Alloy Composition
| Aluminum (Al), % | 0 to 0.020 | |
| 0 |
| Carbon (C), % | 0.080 to 0.12 | |
| 1.2 to 1.3 |
| Chromium (Cr), % | 8.0 to 9.5 | |
| 3.8 to 4.5 |
| Copper (Cu), % | 0 | |
| 0 to 0.25 |
| Iron (Fe), % | 87.3 to 90.3 | |
| 75.8 to 82.3 |
| Manganese (Mn), % | 0.3 to 0.6 | |
| 0.15 to 0.4 |
| Molybdenum (Mo), % | 0.85 to 1.1 | |
| 4.8 to 6.5 |
| Nickel (Ni), % | 0 to 0.4 | |
| 0 to 0.3 |
| Niobium (Nb), % | 0.060 to 0.1 | |
| 0 |
| Nitrogen (N), % | 0.030 to 0.070 | |
| 0 |
| Phosphorus (P), % | 0 to 0.020 | |
| 0 to 0.030 |
| Silicon (Si), % | 0.2 to 0.5 | |
| 0.2 to 0.45 |
| Sulfur (S), % | 0 to 0.010 | |
| 0 to 0.030 |
| Titanium (Ti), % | 0 to 0.010 | |
| 0 |
| Tungsten (W), % | 0 | |
| 5.0 to 6.8 |
| Vanadium (V), % | 0.18 to 0.25 | |
| 2.8 to 3.8 |
| Zirconium (Zr), % | 0 to 0.010 | |
| 0 |