AISI 440A Stainless Steel vs. ASTM A227 Spring Steel
Both AISI 440A stainless steel and ASTM A227 spring steel are iron alloys. They have 82% of their average alloy composition in common. There are 29 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 AISI 440A stainless steel and the bottom bar is ASTM A227 spring steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 200 | |
| 190 |
| Elongation at Break, % | 5.0 to 20 | |
| 12 |
| Fatigue Strength, MPa | 270 to 790 | |
| 900 to 1160 |
| Poisson's Ratio | 0.28 | |
| 0.29 |
| Shear Modulus, GPa | 77 | |
| 72 |
| Shear Strength, MPa | 450 to 1040 | |
| 1030 to 1330 |
| Tensile Strength: Ultimate (UTS), MPa | 730 to 1790 | |
| 1720 to 2220 |
| Tensile Strength: Yield (Proof), MPa | 420 to 1650 | |
| 1430 to 1850 |
Thermal Properties
| Latent Heat of Fusion, J/g | 280 | |
| 250 |
| Maximum Temperature: Mechanical, °C | 760 | |
| 400 |
| Melting Completion (Liquidus), °C | 1480 | |
| 1450 |
| Melting Onset (Solidus), °C | 1370 | |
| 1410 |
| Specific Heat Capacity, J/kg-K | 480 | |
| 470 |
| Thermal Conductivity, W/m-K | 23 | |
| 52 |
| Thermal Expansion, µm/m-K | 10 | |
| 12 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 2.5 | |
| 7.2 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 2.9 | |
| 8.3 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 9.0 | |
| 1.8 |
| Density, g/cm3 | 7.7 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 2.2 | |
| 1.4 |
| Embodied Energy, MJ/kg | 31 | |
| 19 |
| Embodied Water, L/kg | 120 | |
| 46 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 87 to 120 | |
| 200 to 260 |
| Stiffness to Weight: Axial, points | 14 | |
| 13 |
| Stiffness to Weight: Bending, points | 25 | |
| 24 |
| Strength to Weight: Axial, points | 26 to 65 | |
| 61 to 79 |
| Strength to Weight: Bending, points | 23 to 43 | |
| 41 to 48 |
| Thermal Diffusivity, mm2/s | 6.2 | |
| 14 |
| Thermal Shock Resistance, points | 26 to 65 | |
| 55 to 71 |
Alloy Composition
| Carbon (C), % | 0.6 to 0.75 | |
| 0.45 to 0.85 |
| Chromium (Cr), % | 16 to 18 | |
| 0 |
| Iron (Fe), % | 78.4 to 83.4 | |
| 97.4 to 99.1 |
| Manganese (Mn), % | 0 to 1.0 | |
| 0.3 to 1.3 |
| Molybdenum (Mo), % | 0 to 0.75 | |
| 0 |
| Phosphorus (P), % | 0 to 0.040 | |
| 0 to 0.040 |
| Silicon (Si), % | 0 to 1.0 | |
| 0.15 to 0.35 |
| Sulfur (S), % | 0 to 0.015 | |
| 0 to 0.050 |