ASTM A369 Grade FPA vs. SAE-AISI 4042 Steel
Both ASTM A369 grade FPA and SAE-AISI 4042 steel are iron alloys. Their average alloy composition is basically identical.
For each property being compared, the top bar is ASTM A369 grade FPA and the bottom bar is SAE-AISI 4042 steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 110 | |
| 200 |
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 190 |
| Elongation at Break, % | 27 | |
| 13 |
| Fatigue Strength, MPa | 180 | |
| 360 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Shear Modulus, GPa | 73 | |
| 73 |
| Shear Strength, MPa | 240 | |
| 410 |
| Tensile Strength: Ultimate (UTS), MPa | 380 | |
| 680 |
| Tensile Strength: Yield (Proof), MPa | 240 | |
| 570 |
Thermal Properties
| Latent Heat of Fusion, J/g | 250 | |
| 250 |
| Maximum Temperature: Mechanical, °C | 400 | |
| 400 |
| 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 | 52 | |
| 49 |
| Thermal Expansion, µm/m-K | 12 | |
| 12 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 7.1 | |
| 7.1 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 8.1 | |
| 8.2 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 1.8 | |
| 2.1 |
| Density, g/cm3 | 7.8 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 1.4 | |
| 1.5 |
| Embodied Energy, MJ/kg | 18 | |
| 19 |
| Embodied Water, L/kg | 46 | |
| 47 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 89 | |
| 81 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 150 | |
| 860 |
| Stiffness to Weight: Axial, points | 13 | |
| 13 |
| Stiffness to Weight: Bending, points | 24 | |
| 24 |
| Strength to Weight: Axial, points | 13 | |
| 24 |
| Strength to Weight: Bending, points | 15 | |
| 22 |
| Thermal Diffusivity, mm2/s | 14 | |
| 13 |
| Thermal Shock Resistance, points | 12 | |
| 22 |
Alloy Composition
| Carbon (C), % | 0 to 0.25 | |
| 0.4 to 0.45 |
| Iron (Fe), % | 98.3 to 99.63 | |
| 97.9 to 98.6 |
| Manganese (Mn), % | 0.27 to 0.93 | |
| 0.7 to 0.9 |
| Molybdenum (Mo), % | 0 | |
| 0.2 to 0.3 |
| Phosphorus (P), % | 0 to 0.035 | |
| 0 to 0.035 |
| Silicon (Si), % | 0.1 to 0.5 | |
| 0.15 to 0.35 |
| Sulfur (S), % | 0 to 0.035 | |
| 0 to 0.040 |