S21800 Stainless Steel vs. ASTM B780 Alloy
S21800 stainless steel belongs to the iron alloys classification, while ASTM B780 alloy 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.
For each property being compared, the top bar is S21800 stainless steel and the bottom bar is ASTM B780 alloy.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 83 |
| Elongation at Break, % | 40 | |
| 1.1 to 9.1 |
| Poisson's Ratio | 0.28 | |
| 0.36 |
| Shear Modulus, GPa | 75 | |
| 30 |
| Shear Strength, MPa | 510 | |
| 200 to 340 |
| Tensile Strength: Ultimate (UTS), MPa | 740 | |
| 330 to 590 |
Thermal Properties
| Latent Heat of Fusion, J/g | 340 | |
| 140 |
| Specific Heat Capacity, J/kg-K | 500 | |
| 270 |
| Thermal Expansion, µm/m-K | 16 | |
| 18 |
Otherwise Unclassified Properties
| Density, g/cm3 | 7.5 | |
| 10 |
Common Calculations
| Stiffness to Weight: Axial, points | 14 | |
| 4.5 |
| Stiffness to Weight: Bending, points | 26 | |
| 14 |
| Strength to Weight: Axial, points | 27 | |
| 9.1 to 16 |
| Strength to Weight: Bending, points | 24 | |
| 11 to 15 |
| Thermal Shock Resistance, points | 17 | |
| 16 to 29 |
Alloy Composition
| Cadmium (Cd), % | 0 | |
| 0 to 0.050 |
| Carbon (C), % | 0 to 0.1 | |
| 0 |
| Chromium (Cr), % | 16 to 18 | |
| 0 |
| Copper (Cu), % | 0 | |
| 23.5 to 25.7 |
| Iron (Fe), % | 59.1 to 65.4 | |
| 0 to 0.050 |
| Lead (Pb), % | 0 | |
| 0 to 0.030 |
| Manganese (Mn), % | 7.0 to 9.0 | |
| 0 |
| Nickel (Ni), % | 8.0 to 9.0 | |
| 0.35 to 0.65 |
| Nitrogen (N), % | 0.080 to 0.18 | |
| 0 |
| Phosphorus (P), % | 0 to 0.060 | |
| 0 |
| Silicon (Si), % | 3.5 to 4.5 | |
| 0 |
| Silver (Ag), % | 0 | |
| 74 to 76 |
| Sulfur (S), % | 0 to 0.030 | |
| 0 |
| Zinc (Zn), % | 0 | |
| 0 to 0.060 |