ASTM B780 Alloy vs. SAE-AISI 4340M Steel
ASTM B780 alloy belongs to the otherwise unclassified metals classification, while SAE-AISI 4340M steel belongs to the iron alloys. There are 17 material properties with values for both materials. Properties with values for just one material (18, in this case) are not shown.
For each property being compared, the top bar is ASTM B780 alloy and the bottom bar is SAE-AISI 4340M steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 83 | |
| 190 |
| Elongation at Break, % | 1.1 to 9.1 | |
| 6.0 |
| Poisson's Ratio | 0.36 | |
| 0.29 |
| Shear Modulus, GPa | 30 | |
| 72 |
| Shear Strength, MPa | 200 to 340 | |
| 1360 |
| Tensile Strength: Ultimate (UTS), MPa | 330 to 590 | |
| 2340 |
Thermal Properties
| Latent Heat of Fusion, J/g | 140 | |
| 280 |
| Specific Heat Capacity, J/kg-K | 270 | |
| 480 |
| Thermal Expansion, µm/m-K | 18 | |
| 13 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 70 to 76 | |
| 7.8 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 62 to 68 | |
| 9.1 |
Otherwise Unclassified Properties
| Density, g/cm3 | 10 | |
| 7.8 |
Common Calculations
| Stiffness to Weight: Axial, points | 4.5 | |
| 13 |
| Stiffness to Weight: Bending, points | 14 | |
| 25 |
| Strength to Weight: Axial, points | 9.1 to 16 | |
| 84 |
| Strength to Weight: Bending, points | 11 to 15 | |
| 51 |
| Thermal Shock Resistance, points | 16 to 29 | |
| 70 |
Alloy Composition
| Cadmium (Cd), % | 0 to 0.050 | |
| 0 |
| Carbon (C), % | 0 | |
| 0.38 to 0.43 |
| Chromium (Cr), % | 0 | |
| 0.7 to 1.0 |
| Copper (Cu), % | 23.5 to 25.7 | |
| 0 |
| Iron (Fe), % | 0 to 0.050 | |
| 93.3 to 94.8 |
| Lead (Pb), % | 0 to 0.030 | |
| 0 |
| Manganese (Mn), % | 0 | |
| 0.65 to 0.9 |
| Molybdenum (Mo), % | 0 | |
| 0.35 to 0.45 |
| Nickel (Ni), % | 0.35 to 0.65 | |
| 1.7 to 2.0 |
| Phosphorus (P), % | 0 | |
| 0 to 0.012 |
| Silicon (Si), % | 0 | |
| 1.5 to 1.8 |
| Silver (Ag), % | 74 to 76 | |
| 0 |
| Sulfur (S), % | 0 | |
| 0 to 0.012 |
| Vanadium (V), % | 0 | |
| 0.050 to 0.1 |
| Zinc (Zn), % | 0 to 0.060 | |
| 0 |