ASTM A372 Grade J Steel vs. ASTM A387 Grade 12 Steel
Both ASTM A372 grade J steel and ASTM A387 grade 12 steel are iron alloys. Their average alloy composition is basically identical. There are 31 material properties with values for both materials. Properties with values for just one material (1, in this case) are not shown.
For each property being compared, the top bar is ASTM A372 grade J steel and the bottom bar is ASTM A387 grade 12 steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 200 to 310 | |
| 140 to 160 |
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 190 |
| Elongation at Break, % | 17 to 22 | |
| 25 |
| Fatigue Strength, MPa | 310 to 570 | |
| 190 to 230 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Shear Modulus, GPa | 73 | |
| 73 |
| Shear Strength, MPa | 410 to 630 | |
| 300 to 330 |
| Tensile Strength: Ultimate (UTS), MPa | 650 to 1020 | |
| 470 to 520 |
| Tensile Strength: Yield (Proof), MPa | 430 to 850 | |
| 260 to 310 |
Thermal Properties
| Latent Heat of Fusion, J/g | 250 | |
| 250 |
| Maximum Temperature: Mechanical, °C | 420 | |
| 430 |
| Melting Completion (Liquidus), °C | 1460 | |
| 1470 |
| Melting Onset (Solidus), °C | 1420 | |
| 1420 |
| Specific Heat Capacity, J/kg-K | 470 | |
| 470 |
| Thermal Conductivity, W/m-K | 44 | |
| 44 |
| Thermal Expansion, µm/m-K | 13 | |
| 13 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 7.3 | |
| 7.2 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 8.4 | |
| 8.3 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 2.4 | |
| 2.8 |
| Density, g/cm3 | 7.8 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 1.5 | |
| 1.6 |
| Embodied Energy, MJ/kg | 20 | |
| 21 |
| Embodied Water, L/kg | 51 | |
| 51 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 130 to 170 | |
| 98 to 110 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 500 to 1930 | |
| 180 to 250 |
| Stiffness to Weight: Axial, points | 13 | |
| 13 |
| Stiffness to Weight: Bending, points | 24 | |
| 24 |
| Strength to Weight: Axial, points | 23 to 36 | |
| 16 to 18 |
| Strength to Weight: Bending, points | 21 to 29 | |
| 17 to 18 |
| Thermal Diffusivity, mm2/s | 12 | |
| 12 |
| Thermal Shock Resistance, points | 19 to 30 | |
| 14 to 15 |
Alloy Composition
| Carbon (C), % | 0.35 to 0.5 | |
| 0.050 to 0.17 |
| Chromium (Cr), % | 0.8 to 1.2 | |
| 0.8 to 1.2 |
| Iron (Fe), % | 96.7 to 97.8 | |
| 97 to 98.2 |
| Manganese (Mn), % | 0.75 to 1.1 | |
| 0.4 to 0.65 |
| Molybdenum (Mo), % | 0.15 to 0.25 | |
| 0.45 to 0.6 |
| Phosphorus (P), % | 0 to 0.015 | |
| 0 to 0.025 |
| Silicon (Si), % | 0.15 to 0.35 | |
| 0.15 to 0.4 |
| Sulfur (S), % | 0 to 0.010 | |
| 0 to 0.025 |