Ductile Cast Iron vs. SAE-AISI H21 Steel
Both ductile cast iron and SAE-AISI H21 steel are iron alloys. They have a moderately high 91% of their average alloy composition in common. 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 ductile cast iron and the bottom bar is SAE-AISI H21 steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 170 to 180 | |
| 200 |
| Poisson's Ratio | 0.28 to 0.31 | |
| 0.29 |
| Shear Modulus, GPa | 64 to 70 | |
| 76 |
| Tensile Strength: Ultimate (UTS), MPa | 460 to 920 | |
| 720 to 1790 |
Thermal Properties
| Latent Heat of Fusion, J/g | 270 | |
| 250 |
| Melting Completion (Liquidus), °C | 1160 | |
| 1630 |
| Melting Onset (Solidus), °C | 1120 | |
| 1580 |
| Specific Heat Capacity, J/kg-K | 490 | |
| 440 |
| Thermal Conductivity, W/m-K | 31 to 36 | |
| 27 |
| Thermal Expansion, µm/m-K | 11 | |
| 11 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 1.9 | |
| 23 |
| Density, g/cm3 | 7.1 to 7.5 | |
| 8.5 |
| Embodied Carbon, kg CO2/kg material | 1.5 | |
| 4.5 |
| Embodied Energy, MJ/kg | 21 | |
| 68 |
| Embodied Water, L/kg | 43 | |
| 72 |
Common Calculations
| Stiffness to Weight: Axial, points | 12 to 14 | |
| 13 |
| Stiffness to Weight: Bending, points | 24 to 26 | |
| 23 |
| Strength to Weight: Axial, points | 17 to 35 | |
| 23 to 58 |
| Strength to Weight: Bending, points | 18 to 29 | |
| 21 to 38 |
| Thermal Diffusivity, mm2/s | 8.9 to 10 | |
| 7.1 |
| Thermal Shock Resistance, points | 17 to 35 | |
| 24 to 59 |
Alloy Composition
| Carbon (C), % | 3.0 to 3.5 | |
| 0.28 to 0.36 |
| Chromium (Cr), % | 0 | |
| 3.0 to 3.8 |
| Copper (Cu), % | 0 | |
| 0 to 0.25 |
| Iron (Fe), % | 93.7 to 95.5 | |
| 87.6 to 93.8 |
| Manganese (Mn), % | 0 | |
| 0.15 to 0.4 |
| Nickel (Ni), % | 0 | |
| 0 to 0.3 |
| Phosphorus (P), % | 0 to 0.080 | |
| 0 to 0.030 |
| Silicon (Si), % | 1.5 to 2.8 | |
| 0.15 to 0.5 |
| Sulfur (S), % | 0 | |
| 0 to 0.030 |
| Tungsten (W), % | 0 | |
| 8.5 to 10 |
| Vanadium (V), % | 0 | |
| 0.3 to 0.6 |