SAE-AISI 1078 Steel vs. ASTM A387 Grade 21 Steel
Both SAE-AISI 1078 steel and ASTM A387 grade 21 steel are iron alloys. They have a very high 96% of their average alloy composition in common. There are 31 material properties with values for both materials. Properties with values for just one material (2, in this case) are not shown.
For each property being compared, the top bar is SAE-AISI 1078 steel and the bottom bar is ASTM A387 grade 21 steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 220 to 230 | |
| 150 to 180 |
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 190 |
| Elongation at Break, % | 11 to 14 | |
| 21 |
| Fatigue Strength, MPa | 270 to 350 | |
| 160 to 250 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Shear Modulus, GPa | 72 | |
| 74 |
| Shear Strength, MPa | 440 to 470 | |
| 310 to 370 |
| Tensile Strength: Ultimate (UTS), MPa | 730 to 780 | |
| 500 to 590 |
| Tensile Strength: Yield (Proof), MPa | 430 to 570 | |
| 230 to 350 |
Thermal Properties
| Latent Heat of Fusion, J/g | 250 | |
| 260 |
| Maximum Temperature: Mechanical, °C | 400 | |
| 480 |
| Melting Completion (Liquidus), °C | 1460 | |
| 1470 |
| Melting Onset (Solidus), °C | 1420 | |
| 1430 |
| Specific Heat Capacity, J/kg-K | 470 | |
| 470 |
| Thermal Conductivity, W/m-K | 49 | |
| 41 |
| Thermal Expansion, µm/m-K | 11 | |
| 13 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 7.0 | |
| 7.6 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 8.1 | |
| 8.8 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 1.8 | |
| 4.1 |
| Density, g/cm3 | 7.8 | |
| 7.9 |
| Embodied Carbon, kg CO2/kg material | 1.4 | |
| 1.8 |
| Embodied Energy, MJ/kg | 18 | |
| 23 |
| Embodied Water, L/kg | 45 | |
| 62 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 77 to 90 | |
| 84 to 110 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 490 to 860 | |
| 140 to 320 |
| Stiffness to Weight: Axial, points | 13 | |
| 13 |
| Stiffness to Weight: Bending, points | 24 | |
| 24 |
| Strength to Weight: Axial, points | 26 to 28 | |
| 18 to 21 |
| Strength to Weight: Bending, points | 23 to 24 | |
| 18 to 20 |
| Thermal Diffusivity, mm2/s | 13 | |
| 11 |
| Thermal Shock Resistance, points | 25 to 26 | |
| 14 to 17 |
Alloy Composition
| Carbon (C), % | 0.72 to 0.85 | |
| 0.050 to 0.15 |
| Chromium (Cr), % | 0 | |
| 2.8 to 3.3 |
| Iron (Fe), % | 98.5 to 99 | |
| 94.4 to 96 |
| Manganese (Mn), % | 0.3 to 0.6 | |
| 0.3 to 0.6 |
| Molybdenum (Mo), % | 0 | |
| 0.9 to 1.1 |
| Phosphorus (P), % | 0 to 0.040 | |
| 0 to 0.025 |
| Silicon (Si), % | 0 | |
| 0 to 0.5 |
| Sulfur (S), % | 0 to 0.050 | |
| 0 to 0.025 |