SAE-AISI 8645 Steel vs. ASTM A372 Grade M Steel
Both SAE-AISI 8645 steel and ASTM A372 grade M steel are iron alloys. They have a very high 96% 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 SAE-AISI 8645 steel and the bottom bar is ASTM A372 grade M steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 180 to 200 | |
| 240 to 280 |
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 190 |
| Elongation at Break, % | 12 to 23 | |
| 18 to 21 |
| Fatigue Strength, MPa | 280 to 350 | |
| 450 to 520 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Shear Modulus, GPa | 73 | |
| 73 |
| Shear Strength, MPa | 380 to 400 | |
| 510 to 570 |
| Tensile Strength: Ultimate (UTS), MPa | 600 to 670 | |
| 810 to 910 |
| Tensile Strength: Yield (Proof), MPa | 390 to 560 | |
| 660 to 770 |
Thermal Properties
| Latent Heat of Fusion, J/g | 250 | |
| 250 |
| Maximum Temperature: Mechanical, °C | 410 | |
| 450 |
| 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 | 39 | |
| 46 |
| Thermal Expansion, µm/m-K | 13 | |
| 13 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 7.3 | |
| 8.0 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 8.4 | |
| 9.1 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 2.6 | |
| 5.0 |
| Density, g/cm3 | 7.8 | |
| 7.9 |
| Embodied Carbon, kg CO2/kg material | 1.5 | |
| 2.0 |
| Embodied Energy, MJ/kg | 20 | |
| 27 |
| Embodied Water, L/kg | 50 | |
| 61 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 77 to 120 | |
| 160 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 420 to 840 | |
| 1140 to 1580 |
| Stiffness to Weight: Axial, points | 13 | |
| 13 |
| Stiffness to Weight: Bending, points | 24 | |
| 24 |
| Strength to Weight: Axial, points | 21 to 24 | |
| 29 to 32 |
| Strength to Weight: Bending, points | 20 to 22 | |
| 24 to 27 |
| Thermal Diffusivity, mm2/s | 10 | |
| 12 |
| Thermal Shock Resistance, points | 18 to 20 | |
| 24 to 27 |
Alloy Composition
| Carbon (C), % | 0.43 to 0.48 | |
| 0 to 0.23 |
| Chromium (Cr), % | 0.4 to 0.6 | |
| 1.5 to 2.0 |
| Iron (Fe), % | 96.5 to 97.7 | |
| 92.5 to 95.1 |
| Manganese (Mn), % | 0.75 to 1.0 | |
| 0.2 to 0.4 |
| Molybdenum (Mo), % | 0.15 to 0.25 | |
| 0.4 to 0.6 |
| Nickel (Ni), % | 0.4 to 0.7 | |
| 2.8 to 3.9 |
| Phosphorus (P), % | 0 to 0.035 | |
| 0 to 0.015 |
| Silicon (Si), % | 0.15 to 0.35 | |
| 0 to 0.3 |
| Sulfur (S), % | 0 to 0.040 | |
| 0 to 0.010 |
| Vanadium (V), % | 0 | |
| 0 to 0.080 |