ASTM A369 Grade FPA vs. ASTM A227 Spring Steel
Both ASTM A369 grade FPA and ASTM A227 spring steel are iron alloys. Their average alloy composition is basically identical. There are 30 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 ASTM A369 grade FPA and the bottom bar is ASTM A227 spring steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 110 | |
| 500 to 640 |
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 190 |
| Elongation at Break, % | 27 | |
| 12 |
| Fatigue Strength, MPa | 180 | |
| 900 to 1160 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Shear Modulus, GPa | 73 | |
| 72 |
| Shear Strength, MPa | 240 | |
| 1030 to 1330 |
| Tensile Strength: Ultimate (UTS), MPa | 380 | |
| 1720 to 2220 |
| Tensile Strength: Yield (Proof), MPa | 240 | |
| 1430 to 1850 |
Thermal Properties
| Latent Heat of Fusion, J/g | 250 | |
| 250 |
| Maximum Temperature: Mechanical, °C | 400 | |
| 400 |
| Melting Completion (Liquidus), °C | 1460 | |
| 1450 |
| Melting Onset (Solidus), °C | 1420 | |
| 1410 |
| Specific Heat Capacity, J/kg-K | 470 | |
| 470 |
| Thermal Conductivity, W/m-K | 52 | |
| 52 |
| Thermal Expansion, µm/m-K | 12 | |
| 12 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 7.1 | |
| 7.2 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 8.1 | |
| 8.3 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 1.8 | |
| 1.8 |
| Density, g/cm3 | 7.8 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 1.4 | |
| 1.4 |
| Embodied Energy, MJ/kg | 18 | |
| 19 |
| Embodied Water, L/kg | 46 | |
| 46 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 89 | |
| 200 to 260 |
| Stiffness to Weight: Axial, points | 13 | |
| 13 |
| Stiffness to Weight: Bending, points | 24 | |
| 24 |
| Strength to Weight: Axial, points | 13 | |
| 61 to 79 |
| Strength to Weight: Bending, points | 15 | |
| 41 to 48 |
| Thermal Diffusivity, mm2/s | 14 | |
| 14 |
| Thermal Shock Resistance, points | 12 | |
| 55 to 71 |
Alloy Composition
| Carbon (C), % | 0 to 0.25 | |
| 0.45 to 0.85 |
| Iron (Fe), % | 98.3 to 99.63 | |
| 97.4 to 99.1 |
| Manganese (Mn), % | 0.27 to 0.93 | |
| 0.3 to 1.3 |
| Phosphorus (P), % | 0 to 0.035 | |
| 0 to 0.040 |
| Silicon (Si), % | 0.1 to 0.5 | |
| 0.15 to 0.35 |
| Sulfur (S), % | 0 to 0.035 | |
| 0 to 0.050 |