ASTM A387 Grade 21 Steel vs. Chromium 33
ASTM A387 grade 21 steel belongs to the iron alloys classification, while chromium 33 belongs to the otherwise unclassified metals. They have a modest 37% of their average alloy composition in common, which, by itself, doesn't mean much. There are 21 material properties with values for both materials. Properties with values for just one material (11, in this case) are not shown.
For each property being compared, the top bar is ASTM A387 grade 21 steel and the bottom bar is chromium 33.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 200 |
| Elongation at Break, % | 21 | |
| 45 |
| Poisson's Ratio | 0.29 | |
| 0.27 |
| Shear Modulus, GPa | 74 | |
| 81 |
| Tensile Strength: Ultimate (UTS), MPa | 500 to 590 | |
| 850 |
| Tensile Strength: Yield (Proof), MPa | 230 to 350 | |
| 430 |
Thermal Properties
| Latent Heat of Fusion, J/g | 260 | |
| 320 |
| Specific Heat Capacity, J/kg-K | 470 | |
| 480 |
| Thermal Expansion, µm/m-K | 13 | |
| 14 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 4.1 | |
| 36 |
| Density, g/cm3 | 7.9 | |
| 7.9 |
| Embodied Carbon, kg CO2/kg material | 1.8 | |
| 6.0 |
| Embodied Energy, MJ/kg | 23 | |
| 84 |
| Embodied Water, L/kg | 62 | |
| 250 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 84 to 110 | |
| 320 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 140 to 320 | |
| 450 |
| Stiffness to Weight: Axial, points | 13 | |
| 14 |
| Stiffness to Weight: Bending, points | 24 | |
| 25 |
| Strength to Weight: Axial, points | 18 to 21 | |
| 30 |
| Strength to Weight: Bending, points | 18 to 20 | |
| 25 |
| Thermal Shock Resistance, points | 14 to 17 | |
| 21 |
Alloy Composition
| Carbon (C), % | 0.050 to 0.15 | |
| 0 to 0.015 |
| Chromium (Cr), % | 2.8 to 3.3 | |
| 31 to 35 |
| Copper (Cu), % | 0 | |
| 0.3 to 1.2 |
| Iron (Fe), % | 94.4 to 96 | |
| 25.7 to 37.9 |
| Manganese (Mn), % | 0.3 to 0.6 | |
| 0 to 2.0 |
| Molybdenum (Mo), % | 0.9 to 1.1 | |
| 0.5 to 2.0 |
| Nickel (Ni), % | 0 | |
| 30 to 33 |
| Nitrogen (N), % | 0 | |
| 0.35 to 0.6 |
| Phosphorus (P), % | 0 to 0.025 | |
| 0 to 0.020 |
| Silicon (Si), % | 0 to 0.5 | |
| 0 to 0.5 |
| Sulfur (S), % | 0 to 0.025 | |
| 0 to 0.010 |