ASTM A369 Grade FP21 vs. ASTM A369 Grade FP91
Both ASTM A369 grade FP21 and ASTM A369 grade FP91 are iron alloys. They have a moderately high 94% of their average alloy composition in common.
For each property being compared, the top bar is ASTM A369 grade FP21 and the bottom bar is ASTM A369 grade FP91.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 140 | |
| 200 |
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 190 |
| Elongation at Break, % | 20 | |
| 19 |
| Fatigue Strength, MPa | 160 | |
| 320 |
| Poisson's Ratio | 0.29 | |
| 0.28 |
| Shear Modulus, GPa | 74 | |
| 75 |
| Shear Strength, MPa | 300 | |
| 410 |
| Tensile Strength: Ultimate (UTS), MPa | 470 | |
| 670 |
| Tensile Strength: Yield (Proof), MPa | 240 | |
| 460 |
Thermal Properties
| Latent Heat of Fusion, J/g | 260 | |
| 270 |
| Maximum Temperature: Mechanical, °C | 470 | |
| 600 |
| Melting Completion (Liquidus), °C | 1470 | |
| 1460 |
| Melting Onset (Solidus), °C | 1430 | |
| 1420 |
| Specific Heat Capacity, J/kg-K | 470 | |
| 470 |
| Thermal Conductivity, W/m-K | 41 | |
| 26 |
| Thermal Expansion, µm/m-K | 13 | |
| 13 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 7.7 | |
| 8.9 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 8.8 | |
| 10 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 4.0 | |
| 7.0 |
| Density, g/cm3 | 7.8 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 1.8 | |
| 2.6 |
| Embodied Energy, MJ/kg | 23 | |
| 37 |
| Embodied Water, L/kg | 61 | |
| 88 |
Common Calculations
| PREN (Pitting Resistance) | 6.2 | |
| 13 |
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 80 | |
| 110 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 150 | |
| 560 |
| Stiffness to Weight: Axial, points | 13 | |
| 14 |
| Stiffness to Weight: Bending, points | 24 | |
| 25 |
| Strength to Weight: Axial, points | 17 | |
| 24 |
| Strength to Weight: Bending, points | 17 | |
| 22 |
| Thermal Diffusivity, mm2/s | 11 | |
| 6.9 |
| Thermal Shock Resistance, points | 14 | |
| 18 |
Alloy Composition
| Aluminum (Al), % | 0 | |
| 0 to 0.020 |
| Carbon (C), % | 0.050 to 0.15 | |
| 0.080 to 0.12 |
| Chromium (Cr), % | 2.7 to 3.4 | |
| 8.0 to 9.5 |
| Iron (Fe), % | 94.3 to 96.2 | |
| 87.3 to 90.3 |
| Manganese (Mn), % | 0.3 to 0.6 | |
| 0.3 to 0.6 |
| Molybdenum (Mo), % | 0.8 to 1.1 | |
| 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 0.025 | |
| 0 to 0.025 |
| Silicon (Si), % | 0 to 0.5 | |
| 0.2 to 0.5 |
| Sulfur (S), % | 0 to 0.025 | |
| 0 to 0.025 |
| Titanium (Ti), % | 0 | |
| 0 to 0.010 |
| Vanadium (V), % | 0 | |
| 0.18 to 0.25 |
| Zirconium (Zr), % | 0 | |
| 0 to 0.010 |