ASTM A372 Grade M Steel vs. SAE-AISI 81B45 Steel
Both ASTM A372 grade M steel and SAE-AISI 81B45 steel are iron alloys. They have a very high 95% of their average alloy composition in common. There are 31 material properties with values for both materials. Properties with values for just one material (1, in this case) are not shown.
For each property being compared, the top bar is ASTM A372 grade M steel and the bottom bar is SAE-AISI 81B45 steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 240 to 280 | |
| 160 to 200 |
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 190 |
| Elongation at Break, % | 18 to 21 | |
| 12 to 24 |
| Fatigue Strength, MPa | 450 to 520 | |
| 250 to 350 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Shear Modulus, GPa | 73 | |
| 73 |
| Shear Strength, MPa | 510 to 570 | |
| 340 to 400 |
| Tensile Strength: Ultimate (UTS), MPa | 810 to 910 | |
| 540 to 670 |
| Tensile Strength: Yield (Proof), MPa | 660 to 770 | |
| 350 to 560 |
Thermal Properties
| Latent Heat of Fusion, J/g | 250 | |
| 250 |
| Maximum Temperature: Mechanical, °C | 450 | |
| 410 |
| Melting Completion (Liquidus), °C | 1460 | |
| 1460 |
| Melting Onset (Solidus), °C | 1420 | |
| 1420 |
| Specific Heat Capacity, J/kg-K | 470 | |
| 470 |
| Thermal Conductivity, W/m-K | 46 | |
| 40 |
| Thermal Expansion, µm/m-K | 13 | |
| 12 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 8.0 | |
| 7.2 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 9.1 | |
| 8.3 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 5.0 | |
| 2.3 |
| Density, g/cm3 | 7.9 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 2.0 | |
| 1.5 |
| Embodied Energy, MJ/kg | 27 | |
| 20 |
| Embodied Water, L/kg | 61 | |
| 49 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 160 | |
| 77 to 110 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 1140 to 1580 | |
| 320 to 840 |
| Stiffness to Weight: Axial, points | 13 | |
| 13 |
| Stiffness to Weight: Bending, points | 24 | |
| 24 |
| Strength to Weight: Axial, points | 29 to 32 | |
| 19 to 24 |
| Strength to Weight: Bending, points | 24 to 27 | |
| 19 to 22 |
| Thermal Diffusivity, mm2/s | 12 | |
| 11 |
| Thermal Shock Resistance, points | 24 to 27 | |
| 17 to 21 |
Alloy Composition
| Boron (B), % | 0 | |
| 0.00050 to 0.0030 |
| Carbon (C), % | 0 to 0.23 | |
| 0.43 to 0.48 |
| Chromium (Cr), % | 1.5 to 2.0 | |
| 0.35 to 0.55 |
| Iron (Fe), % | 92.5 to 95.1 | |
| 97 to 98 |
| Manganese (Mn), % | 0.2 to 0.4 | |
| 0.75 to 1.0 |
| Molybdenum (Mo), % | 0.4 to 0.6 | |
| 0.080 to 0.15 |
| Nickel (Ni), % | 2.8 to 3.9 | |
| 0.2 to 0.4 |
| Phosphorus (P), % | 0 to 0.015 | |
| 0 to 0.035 |
| Silicon (Si), % | 0 to 0.3 | |
| 0.15 to 0.35 |
| Sulfur (S), % | 0 to 0.010 | |
| 0 to 0.040 |
| Vanadium (V), % | 0 to 0.080 | |
| 0 |