ASTM A372 Grade H Steel vs. ASTM A387 Grade 91 Class 2
Both ASTM A372 grade H steel and ASTM A387 grade 91 class 2 are iron alloys. They have a moderately high 90% of their average alloy composition in common. 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 H steel and the bottom bar is ASTM A387 grade 91 class 2.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 200 to 280 | |
| 200 |
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 190 |
| Elongation at Break, % | 20 to 22 | |
| 20 |
| Fatigue Strength, MPa | 310 to 380 | |
| 330 |
| Poisson's Ratio | 0.29 | |
| 0.28 |
| Shear Modulus, GPa | 73 | |
| 75 |
| Shear Strength, MPa | 410 to 570 | |
| 420 |
| Tensile Strength: Ultimate (UTS), MPa | 650 to 910 | |
| 670 |
| Tensile Strength: Yield (Proof), MPa | 430 to 550 | |
| 470 |
Thermal Properties
| Latent Heat of Fusion, J/g | 250 | |
| 270 |
| Maximum Temperature: Mechanical, °C | 410 | |
| 600 |
| Melting Completion (Liquidus), °C | 1460 | |
| 1460 |
| Melting Onset (Solidus), °C | 1420 | |
| 1420 |
| Specific Heat Capacity, J/kg-K | 470 | |
| 470 |
| Thermal Conductivity, W/m-K | 45 | |
| 26 |
| Thermal Expansion, µm/m-K | 13 | |
| 13 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 7.2 | |
| 8.9 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 8.3 | |
| 10 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 2.3 | |
| 7.0 |
| Density, g/cm3 | 7.8 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 1.5 | |
| 2.6 |
| Embodied Energy, MJ/kg | 20 | |
| 37 |
| Embodied Water, L/kg | 49 | |
| 88 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 130 to 160 | |
| 120 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 500 to 810 | |
| 580 |
| Stiffness to Weight: Axial, points | 13 | |
| 14 |
| Stiffness to Weight: Bending, points | 24 | |
| 25 |
| Strength to Weight: Axial, points | 23 to 32 | |
| 24 |
| Strength to Weight: Bending, points | 21 to 27 | |
| 22 |
| Thermal Diffusivity, mm2/s | 12 | |
| 6.9 |
| Thermal Shock Resistance, points | 19 to 27 | |
| 19 |
Alloy Composition
| Aluminum (Al), % | 0 | |
| 0 to 0.020 |
| Carbon (C), % | 0.3 to 0.4 | |
| 0.080 to 0.12 |
| Chromium (Cr), % | 0.4 to 0.65 | |
| 8.0 to 9.5 |
| Iron (Fe), % | 97.3 to 98.3 | |
| 87.3 to 90.3 |
| Manganese (Mn), % | 0.75 to 1.1 | |
| 0.3 to 0.6 |
| Molybdenum (Mo), % | 0.15 to 0.25 | |
| 0.85 to 1.1 |
| Nickel (Ni), % | 0 | |
| 0 to 0.4 |
| Niobium (Nb), % | 0 | |
| 0.060 to 0.1 |
| Nitrogen (N), % | 0 | |
| 0.030 to 0.070 |
| Phosphorus (P), % | 0 to 0.015 | |
| 0 to 0.020 |
| Silicon (Si), % | 0.15 to 0.35 | |
| 0.2 to 0.5 |
| Sulfur (S), % | 0 to 0.010 | |
| 0 to 0.010 |
| Titanium (Ti), % | 0 | |
| 0 to 0.010 |
| Vanadium (V), % | 0 | |
| 0.18 to 0.25 |
| Zirconium (Zr), % | 0 | |
| 0 to 0.010 |