ASTM A231 Spring Steel vs. ASTM A372 Grade M Steel
Both ASTM A231 spring steel and ASTM A372 grade M steel are iron alloys. They have a very high 95% of their average alloy composition in common. There are 30 material properties with values for both materials. Properties with values for just one material (3, in this case) are not shown.
For each property being compared, the top bar is ASTM A231 spring steel and the bottom bar is ASTM A372 grade M steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 540 | |
| 240 to 280 |
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 190 |
| Elongation at Break, % | 14 | |
| 18 to 21 |
| Fatigue Strength, MPa | 1000 | |
| 450 to 520 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Shear Modulus, GPa | 73 | |
| 73 |
| Shear Strength, MPa | 1080 | |
| 510 to 570 |
| Tensile Strength: Ultimate (UTS), MPa | 1790 | |
| 810 to 910 |
| Tensile Strength: Yield (Proof), MPa | 1570 | |
| 660 to 770 |
Thermal Properties
| Latent Heat of Fusion, J/g | 250 | |
| 250 |
| Maximum Temperature: Mechanical, °C | 420 | |
| 450 |
| 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 | |
| 46 |
| Thermal Expansion, µm/m-K | 13 | |
| 13 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 7.3 | |
| 8.0 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 8.4 | |
| 9.1 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 2.3 | |
| 5.0 |
| Density, g/cm3 | 7.8 | |
| 7.9 |
| Embodied Carbon, kg CO2/kg material | 2.0 | |
| 2.0 |
| Embodied Energy, MJ/kg | 28 | |
| 27 |
| Embodied Water, L/kg | 51 | |
| 61 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 230 | |
| 160 |
| Stiffness to Weight: Axial, points | 13 | |
| 13 |
| Stiffness to Weight: Bending, points | 24 | |
| 24 |
| Strength to Weight: Axial, points | 64 | |
| 29 to 32 |
| Strength to Weight: Bending, points | 42 | |
| 24 to 27 |
| Thermal Diffusivity, mm2/s | 14 | |
| 12 |
| Thermal Shock Resistance, points | 53 | |
| 24 to 27 |
Alloy Composition
| Carbon (C), % | 0.48 to 0.53 | |
| 0 to 0.23 |
| Chromium (Cr), % | 0.8 to 1.1 | |
| 1.5 to 2.0 |
| Iron (Fe), % | 96.7 to 97.7 | |
| 92.5 to 95.1 |
| Manganese (Mn), % | 0.7 to 0.9 | |
| 0.2 to 0.4 |
| Molybdenum (Mo), % | 0 | |
| 0.4 to 0.6 |
| Nickel (Ni), % | 0 | |
| 2.8 to 3.9 |
| Phosphorus (P), % | 0 to 0.040 | |
| 0 to 0.015 |
| Silicon (Si), % | 0.15 to 0.35 | |
| 0 to 0.3 |
| Sulfur (S), % | 0 to 0.040 | |
| 0 to 0.010 |
| Vanadium (V), % | 0.15 to 0.3 | |
| 0 to 0.080 |