SAE-AISI P21 Steel vs. ASTM A369 Grade FP91
Both SAE-AISI P21 steel and ASTM A369 grade FP91 are iron alloys. They have a moderately high 90% of their average alloy composition in common. There are 23 material properties with values for both materials. Properties with values for just one material (10, in this case) are not shown.
For each property being compared, the top bar is SAE-AISI P21 steel and the bottom bar is ASTM A369 grade FP91.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 190 |
| Poisson's Ratio | 0.29 | |
| 0.28 |
| Shear Modulus, GPa | 73 | |
| 75 |
| Tensile Strength: Ultimate (UTS), MPa | 1130 | |
| 670 |
Thermal Properties
| Latent Heat of Fusion, J/g | 250 | |
| 270 |
| Melting Completion (Liquidus), °C | 1450 | |
| 1460 |
| Melting Onset (Solidus), °C | 1410 | |
| 1420 |
| Specific Heat Capacity, J/kg-K | 470 | |
| 470 |
| Thermal Conductivity, W/m-K | 41 | |
| 26 |
| Thermal Expansion, µm/m-K | 12 | |
| 13 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 7.9 | |
| 8.9 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 9.0 | |
| 10 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 6.5 | |
| 7.0 |
| Density, g/cm3 | 7.9 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 2.3 | |
| 2.6 |
| Embodied Energy, MJ/kg | 32 | |
| 37 |
| Embodied Water, L/kg | 62 | |
| 88 |
Common Calculations
| Stiffness to Weight: Axial, points | 13 | |
| 14 |
| Stiffness to Weight: Bending, points | 24 | |
| 25 |
| Strength to Weight: Axial, points | 40 | |
| 24 |
| Strength to Weight: Bending, points | 31 | |
| 22 |
| Thermal Diffusivity, mm2/s | 11 | |
| 6.9 |
| Thermal Shock Resistance, points | 37 | |
| 18 |
Alloy Composition
| Aluminum (Al), % | 0 | |
| 0 to 0.020 |
| Carbon (C), % | 0.18 to 0.22 | |
| 0.080 to 0.12 |
| Chromium (Cr), % | 0 to 0.5 | |
| 8.0 to 9.5 |
| Cobalt (Co), % | 1.1 to 1.3 | |
| 0 |
| Copper (Cu), % | 0 to 0.25 | |
| 0 |
| Iron (Fe), % | 92.1 to 94.2 | |
| 87.3 to 90.3 |
| Manganese (Mn), % | 0.35 to 0.72 | |
| 0.3 to 0.6 |
| Molybdenum (Mo), % | 0 | |
| 0.85 to 1.1 |
| Nickel (Ni), % | 3.9 to 4.3 | |
| 0 to 0.4 |
| Niobium (Nb), % | 0 | |
| 0.060 to 0.1 |
| Nitrogen (N), % | 0 | |
| 0.030 to 0.070 |
| Phosphorus (P), % | 0 to 0.030 | |
| 0 to 0.025 |
| Silicon (Si), % | 0.2 to 0.4 | |
| 0.2 to 0.5 |
| Sulfur (S), % | 0 to 0.030 | |
| 0 to 0.025 |
| Titanium (Ti), % | 0 | |
| 0 to 0.010 |
| Vanadium (V), % | 0.15 to 0.25 | |
| 0.18 to 0.25 |
| Zirconium (Zr), % | 0 | |
| 0 to 0.010 |