ASTM A369 Grade FP21 vs. ASTM A387 Grade 11 Steel
Both ASTM A369 grade FP21 and ASTM A387 grade 11 steel are iron alloys. They have a very high 98% 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 A387 grade 11 steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 140 | |
| 150 to 180 |
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 190 |
| Elongation at Break, % | 20 | |
| 25 |
| Fatigue Strength, MPa | 160 | |
| 200 to 250 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Shear Modulus, GPa | 74 | |
| 73 |
| Shear Strength, MPa | 300 | |
| 320 to 390 |
| Tensile Strength: Ultimate (UTS), MPa | 470 | |
| 500 to 600 |
| Tensile Strength: Yield (Proof), MPa | 240 | |
| 270 to 350 |
Thermal Properties
| Latent Heat of Fusion, J/g | 260 | |
| 260 |
| Maximum Temperature: Mechanical, °C | 470 | |
| 430 |
| 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 | |
| 39 |
| Thermal Expansion, µm/m-K | 13 | |
| 13 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 7.7 | |
| 7.4 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 8.8 | |
| 8.5 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 4.0 | |
| 2.9 |
| Density, g/cm3 | 7.8 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 1.8 | |
| 1.6 |
| Embodied Energy, MJ/kg | 23 | |
| 21 |
| Embodied Water, L/kg | 61 | |
| 53 |
Common Calculations
| PREN (Pitting Resistance) | 6.2 | |
| 3.1 |
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 80 | |
| 100 to 130 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 150 | |
| 200 to 320 |
| Stiffness to Weight: Axial, points | 13 | |
| 13 |
| Stiffness to Weight: Bending, points | 24 | |
| 24 |
| Strength to Weight: Axial, points | 17 | |
| 18 to 21 |
| Strength to Weight: Bending, points | 17 | |
| 18 to 20 |
| Thermal Diffusivity, mm2/s | 11 | |
| 11 |
| Thermal Shock Resistance, points | 14 | |
| 15 to 18 |
Alloy Composition
| Carbon (C), % | 0.050 to 0.15 | |
| 0.050 to 0.17 |
| Chromium (Cr), % | 2.7 to 3.4 | |
| 1.0 to 1.5 |
| Iron (Fe), % | 94.3 to 96.2 | |
| 96.2 to 97.6 |
| Manganese (Mn), % | 0.3 to 0.6 | |
| 0.4 to 0.65 |
| Molybdenum (Mo), % | 0.8 to 1.1 | |
| 0.45 to 0.65 |
| Phosphorus (P), % | 0 to 0.025 | |
| 0 to 0.025 |
| Silicon (Si), % | 0 to 0.5 | |
| 0.5 to 0.8 |
| Sulfur (S), % | 0 to 0.025 | |
| 0 to 0.025 |