ASTM A387 Grade 21 Steel vs. AWS BAu-2
ASTM A387 grade 21 steel belongs to the iron alloys classification, while AWS BAu-2 belongs to the otherwise unclassified metals. There are 15 material properties with values for both materials. Properties with values for just one material (18, in this case) are not shown. Please note that the two materials have significantly dissimilar densities. This means that additional care is required when interpreting the data, because some material properties are based on units of mass, while others are based on units of area or volume.
For each property being compared, the top bar is ASTM A387 grade 21 steel and the bottom bar is AWS BAu-2.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 100 |
| Poisson's Ratio | 0.29 | |
| 0.4 |
| Shear Modulus, GPa | 74 | |
| 36 |
| Tensile Strength: Ultimate (UTS), MPa | 500 to 590 | |
| 150 |
Thermal Properties
| Latent Heat of Fusion, J/g | 260 | |
| 92 |
| Melting Completion (Liquidus), °C | 1470 | |
| 890 |
| Melting Onset (Solidus), °C | 1430 | |
| 890 |
| Specific Heat Capacity, J/kg-K | 470 | |
| 180 |
| Thermal Expansion, µm/m-K | 13 | |
| 15 |
Otherwise Unclassified Properties
| Density, g/cm3 | 7.9 | |
| 17 |
Common Calculations
| Stiffness to Weight: Axial, points | 13 | |
| 3.3 |
| Stiffness to Weight: Bending, points | 24 | |
| 9.1 |
| Strength to Weight: Axial, points | 18 to 21 | |
| 2.4 |
| Strength to Weight: Bending, points | 18 to 20 | |
| 3.6 |
| Thermal Shock Resistance, points | 14 to 17 | |
| 7.1 |
Alloy Composition
| Carbon (C), % | 0.050 to 0.15 | |
| 0 |
| Chromium (Cr), % | 2.8 to 3.3 | |
| 0 |
| Copper (Cu), % | 0 | |
| 19.4 to 20.5 |
| Gold (Au), % | 0 | |
| 79.5 to 80.5 |
| Iron (Fe), % | 94.4 to 96 | |
| 0 |
| Manganese (Mn), % | 0.3 to 0.6 | |
| 0 |
| Molybdenum (Mo), % | 0.9 to 1.1 | |
| 0 |
| Phosphorus (P), % | 0 to 0.025 | |
| 0 |
| Silicon (Si), % | 0 to 0.5 | |
| 0 |
| Sulfur (S), % | 0 to 0.025 | |
| 0 |
| Residuals, % | 0 | |
| 0 to 0.15 |