Ductile Cast Iron vs. ASTM A387 Grade 21L Class 1
Both ductile cast iron and ASTM A387 grade 21L class 1 are iron alloys. They have a moderately high 95% of their average alloy composition in common. There are 30 material properties with values for both materials. Properties with values for just one material (3, in this case) are not shown.
For each property being compared, the top bar is ductile cast iron and the bottom bar is ASTM A387 grade 21L class 1.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 160 to 310 | |
| 150 |
| Elastic (Young's, Tensile) Modulus, GPa | 170 to 180 | |
| 190 |
| Elongation at Break, % | 2.1 to 20 | |
| 21 |
| Poisson's Ratio | 0.28 to 0.31 | |
| 0.29 |
| Shear Modulus, GPa | 64 to 70 | |
| 74 |
| Shear Strength, MPa | 420 to 800 | |
| 310 |
| Tensile Strength: Ultimate (UTS), MPa | 460 to 920 | |
| 500 |
| Tensile Strength: Yield (Proof), MPa | 310 to 670 | |
| 230 |
Thermal Properties
| Latent Heat of Fusion, J/g | 270 | |
| 260 |
| Maximum Temperature: Mechanical, °C | 290 | |
| 480 |
| Melting Completion (Liquidus), °C | 1160 | |
| 1470 |
| Melting Onset (Solidus), °C | 1120 | |
| 1430 |
| Specific Heat Capacity, J/kg-K | 490 | |
| 470 |
| Thermal Conductivity, W/m-K | 31 to 36 | |
| 41 |
| Thermal Expansion, µm/m-K | 11 | |
| 13 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 7.4 | |
| 7.6 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 8.8 to 9.4 | |
| 8.8 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 1.9 | |
| 4.1 |
| Density, g/cm3 | 7.1 to 7.5 | |
| 7.9 |
| Embodied Carbon, kg CO2/kg material | 1.5 | |
| 1.8 |
| Embodied Energy, MJ/kg | 21 | |
| 23 |
| Embodied Water, L/kg | 43 | |
| 62 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 17 to 80 | |
| 84 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 280 to 1330 | |
| 140 |
| Stiffness to Weight: Axial, points | 12 to 14 | |
| 13 |
| Stiffness to Weight: Bending, points | 24 to 26 | |
| 24 |
| Strength to Weight: Axial, points | 17 to 35 | |
| 18 |
| Strength to Weight: Bending, points | 18 to 29 | |
| 18 |
| Thermal Diffusivity, mm2/s | 8.9 to 10 | |
| 11 |
| Thermal Shock Resistance, points | 17 to 35 | |
| 14 |
Alloy Composition
| Carbon (C), % | 3.0 to 3.5 | |
| 0 to 0.1 |
| Chromium (Cr), % | 0 | |
| 2.8 to 3.3 |
| Iron (Fe), % | 93.7 to 95.5 | |
| 94.4 to 96.1 |
| Manganese (Mn), % | 0 | |
| 0.3 to 0.6 |
| Molybdenum (Mo), % | 0 | |
| 0.9 to 1.1 |
| Phosphorus (P), % | 0 to 0.080 | |
| 0 to 0.025 |
| Silicon (Si), % | 1.5 to 2.8 | |
| 0 to 0.5 |
| Sulfur (S), % | 0 | |
| 0 to 0.025 |