ASTM A232 Spring Steel vs. SAE-AISI 8740 Steel
Both ASTM A232 spring steel and SAE-AISI 8740 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 (2, in this case) are not shown.
For each property being compared, the top bar is ASTM A232 spring steel and the bottom bar is SAE-AISI 8740 steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 540 | |
| 170 to 200 |
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 190 |
| Elongation at Break, % | 14 | |
| 11 to 23 |
| Fatigue Strength, MPa | 1040 | |
| 270 to 350 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Shear Modulus, GPa | 73 | |
| 73 |
| Shear Strength, MPa | 1090 | |
| 370 to 400 |
| Tensile Strength: Ultimate (UTS), MPa | 1790 | |
| 580 to 670 |
| Tensile Strength: Yield (Proof), MPa | 1610 | |
| 380 to 570 |
Thermal Properties
| Latent Heat of Fusion, J/g | 250 | |
| 250 |
| Maximum Temperature: Mechanical, °C | 420 | |
| 410 |
| Melting Completion (Liquidus), °C | 1460 | |
| 1460 |
| Melting Onset (Solidus), °C | 1410 | |
| 1420 |
| Specific Heat Capacity, J/kg-K | 470 | |
| 470 |
| Thermal Conductivity, W/m-K | 52 | |
| 39 |
| Thermal Expansion, µm/m-K | 13 | |
| 13 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 7.3 | |
| 7.3 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 8.4 | |
| 8.4 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 2.3 | |
| 2.6 |
| Density, g/cm3 | 7.8 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 2.0 | |
| 1.5 |
| Embodied Energy, MJ/kg | 28 | |
| 20 |
| Embodied Water, L/kg | 51 | |
| 50 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 250 | |
| 71 to 120 |
| Stiffness to Weight: Axial, points | 13 | |
| 13 |
| Stiffness to Weight: Bending, points | 24 | |
| 24 |
| Strength to Weight: Axial, points | 64 | |
| 20 to 24 |
| Strength to Weight: Bending, points | 42 | |
| 20 to 22 |
| Thermal Diffusivity, mm2/s | 14 | |
| 10 |
| Thermal Shock Resistance, points | 53 | |
| 17 to 20 |
Alloy Composition
| Carbon (C), % | 0.48 to 0.53 | |
| 0.38 to 0.43 |
| Chromium (Cr), % | 0.8 to 1.1 | |
| 0.4 to 0.6 |
| Iron (Fe), % | 96.8 to 97.7 | |
| 96.5 to 97.7 |
| Manganese (Mn), % | 0.7 to 0.9 | |
| 0.75 to 1.0 |
| Molybdenum (Mo), % | 0 | |
| 0.2 to 0.3 |
| Nickel (Ni), % | 0 | |
| 0.4 to 0.7 |
| Phosphorus (P), % | 0 to 0.020 | |
| 0 to 0.035 |
| Silicon (Si), % | 0.15 to 0.35 | |
| 0.15 to 0.35 |
| Sulfur (S), % | 0 to 0.035 | |
| 0 to 0.040 |
| Vanadium (V), % | 0.15 to 0.3 | |
| 0 |