SAE-AISI 81B45 Steel vs. ASTM A387 Grade 2 Steel
Both SAE-AISI 81B45 steel and ASTM A387 grade 2 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 SAE-AISI 81B45 steel and the bottom bar is ASTM A387 grade 2 steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 160 to 200 | |
| 140 to 170 |
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 190 |
| Elongation at Break, % | 12 to 24 | |
| 25 |
| Fatigue Strength, MPa | 250 to 350 | |
| 190 to 250 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Shear Modulus, GPa | 73 | |
| 73 |
| Shear Strength, MPa | 340 to 400 | |
| 300 to 350 |
| Tensile Strength: Ultimate (UTS), MPa | 540 to 670 | |
| 470 to 550 |
| Tensile Strength: Yield (Proof), MPa | 350 to 560 | |
| 260 to 350 |
Thermal Properties
| Latent Heat of Fusion, J/g | 250 | |
| 250 |
| Maximum Temperature: Mechanical, °C | 410 | |
| 420 |
| 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 | 40 | |
| 45 |
| Thermal Expansion, µm/m-K | 12 | |
| 13 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 7.2 | |
| 7.2 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 8.3 | |
| 8.3 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 2.3 | |
| 2.6 |
| Density, g/cm3 | 7.8 | |
| 7.9 |
| Embodied Carbon, kg CO2/kg material | 1.5 | |
| 1.6 |
| Embodied Energy, MJ/kg | 20 | |
| 20 |
| Embodied Water, L/kg | 49 | |
| 50 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 77 to 110 | |
| 98 to 120 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 320 to 840 | |
| 180 to 320 |
| Stiffness to Weight: Axial, points | 13 | |
| 13 |
| Stiffness to Weight: Bending, points | 24 | |
| 24 |
| Strength to Weight: Axial, points | 19 to 24 | |
| 16 to 20 |
| Strength to Weight: Bending, points | 19 to 22 | |
| 17 to 19 |
| Thermal Diffusivity, mm2/s | 11 | |
| 12 |
| Thermal Shock Resistance, points | 17 to 21 | |
| 14 to 16 |
Alloy Composition
| Boron (B), % | 0.00050 to 0.0030 | |
| 0 |
| Carbon (C), % | 0.43 to 0.48 | |
| 0.050 to 0.21 |
| Chromium (Cr), % | 0.35 to 0.55 | |
| 0.5 to 0.8 |
| Iron (Fe), % | 97 to 98 | |
| 97.1 to 98.3 |
| Manganese (Mn), % | 0.75 to 1.0 | |
| 0.55 to 0.8 |
| Molybdenum (Mo), % | 0.080 to 0.15 | |
| 0.45 to 0.6 |
| Nickel (Ni), % | 0.2 to 0.4 | |
| 0 |
| Phosphorus (P), % | 0 to 0.035 | |
| 0 to 0.025 |
| Silicon (Si), % | 0.15 to 0.35 | |
| 0.15 to 0.4 |
| Sulfur (S), % | 0 to 0.040 | |
| 0 to 0.025 |