SAE-AISI 4340M Steel vs. ASTM A372 Grade J Steel
Both SAE-AISI 4340M steel and ASTM A372 grade J steel are iron alloys. They have a very high 97% of their average alloy composition in common. There are 31 material properties with values for both materials. Properties with values for just one material (4, in this case) are not shown.
For each property being compared, the top bar is SAE-AISI 4340M steel and the bottom bar is ASTM A372 grade J steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 710 | |
| 200 to 310 |
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 190 |
| Elongation at Break, % | 6.0 | |
| 17 to 22 |
| Fatigue Strength, MPa | 690 | |
| 310 to 570 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Shear Modulus, GPa | 72 | |
| 73 |
| Shear Strength, MPa | 1360 | |
| 410 to 630 |
| Tensile Strength: Ultimate (UTS), MPa | 2340 | |
| 650 to 1020 |
| Tensile Strength: Yield (Proof), MPa | 1240 | |
| 430 to 850 |
Thermal Properties
| Latent Heat of Fusion, J/g | 280 | |
| 250 |
| Maximum Temperature: Mechanical, °C | 430 | |
| 420 |
| Melting Completion (Liquidus), °C | 1440 | |
| 1460 |
| Melting Onset (Solidus), °C | 1400 | |
| 1420 |
| Specific Heat Capacity, J/kg-K | 480 | |
| 470 |
| Thermal Conductivity, W/m-K | 38 | |
| 44 |
| Thermal Expansion, µm/m-K | 13 | |
| 13 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 7.8 | |
| 7.3 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 9.1 | |
| 8.4 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 3.9 | |
| 2.4 |
| Density, g/cm3 | 7.8 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 1.9 | |
| 1.5 |
| Embodied Energy, MJ/kg | 26 | |
| 20 |
| Embodied Water, L/kg | 55 | |
| 51 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 120 | |
| 130 to 170 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 4120 | |
| 500 to 1930 |
| Stiffness to Weight: Axial, points | 13 | |
| 13 |
| Stiffness to Weight: Bending, points | 25 | |
| 24 |
| Strength to Weight: Axial, points | 84 | |
| 23 to 36 |
| Strength to Weight: Bending, points | 51 | |
| 21 to 29 |
| Thermal Diffusivity, mm2/s | 10 | |
| 12 |
| Thermal Shock Resistance, points | 70 | |
| 19 to 30 |
Alloy Composition
| Carbon (C), % | 0.38 to 0.43 | |
| 0.35 to 0.5 |
| Chromium (Cr), % | 0.7 to 1.0 | |
| 0.8 to 1.2 |
| Iron (Fe), % | 93.3 to 94.8 | |
| 96.7 to 97.8 |
| Manganese (Mn), % | 0.65 to 0.9 | |
| 0.75 to 1.1 |
| Molybdenum (Mo), % | 0.35 to 0.45 | |
| 0.15 to 0.25 |
| Nickel (Ni), % | 1.7 to 2.0 | |
| 0 |
| Phosphorus (P), % | 0 to 0.012 | |
| 0 to 0.015 |
| Silicon (Si), % | 1.5 to 1.8 | |
| 0.15 to 0.35 |
| Sulfur (S), % | 0 to 0.012 | |
| 0 to 0.010 |
| Vanadium (V), % | 0.050 to 0.1 | |
| 0 |