Automotive Malleable Cast Iron vs. ASTM A387 Grade 21 Steel
Both automotive malleable cast iron and ASTM A387 grade 21 steel are iron alloys. They have a very high 96% of their average alloy composition in common. There are 28 material properties with values for both materials. Properties with values for just one material (4, in this case) are not shown.
For each property being compared, the top bar is automotive malleable cast iron and the bottom bar is ASTM A387 grade 21 steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 130 to 290 | |
| 150 to 180 |
| Elastic (Young's, Tensile) Modulus, GPa | 180 | |
| 190 |
| Elongation at Break, % | 1.0 to 10 | |
| 21 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Shear Modulus, GPa | 70 | |
| 74 |
| Tensile Strength: Ultimate (UTS), MPa | 350 to 720 | |
| 500 to 590 |
| Tensile Strength: Yield (Proof), MPa | 220 to 590 | |
| 230 to 350 |
Thermal Properties
| Latent Heat of Fusion, J/g | 260 | |
| 260 |
| Melting Completion (Liquidus), °C | 1410 | |
| 1470 |
| Melting Onset (Solidus), °C | 1370 | |
| 1430 |
| Specific Heat Capacity, J/kg-K | 480 | |
| 470 |
| Thermal Conductivity, W/m-K | 41 | |
| 41 |
| Thermal Expansion, µm/m-K | 14 | |
| 13 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 7.4 | |
| 7.6 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 8.7 | |
| 8.8 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 1.9 | |
| 4.1 |
| Density, g/cm3 | 7.6 | |
| 7.9 |
| Embodied Carbon, kg CO2/kg material | 1.5 | |
| 1.8 |
| Embodied Energy, MJ/kg | 20 | |
| 23 |
| Embodied Water, L/kg | 45 | |
| 62 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 6.8 to 30 | |
| 84 to 110 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 130 to 950 | |
| 140 to 320 |
| Stiffness to Weight: Axial, points | 13 | |
| 13 |
| Stiffness to Weight: Bending, points | 25 | |
| 24 |
| Strength to Weight: Axial, points | 13 to 26 | |
| 18 to 21 |
| Strength to Weight: Bending, points | 14 to 24 | |
| 18 to 20 |
| Thermal Diffusivity, mm2/s | 11 | |
| 11 |
| Thermal Shock Resistance, points | 9.9 to 21 | |
| 14 to 17 |
Alloy Composition
| Carbon (C), % | 2.2 to 2.9 | |
| 0.050 to 0.15 |
| Chromium (Cr), % | 0 | |
| 2.8 to 3.3 |
| Iron (Fe), % | 93.6 to 96.7 | |
| 94.4 to 96 |
| Manganese (Mn), % | 0.15 to 1.3 | |
| 0.3 to 0.6 |
| Molybdenum (Mo), % | 0 | |
| 0.9 to 1.1 |
| Phosphorus (P), % | 0.020 to 0.15 | |
| 0 to 0.025 |
| Silicon (Si), % | 0.9 to 1.9 | |
| 0 to 0.5 |
| Sulfur (S), % | 0.020 to 0.2 | |
| 0 to 0.025 |