SAE-AISI 4340M Steel vs. S31727 Stainless Steel
Both SAE-AISI 4340M steel and S31727 stainless steel are iron alloys. Both are furnished in the annealed condition. They have 62% of their average alloy composition in common. There are 28 material properties with values for both materials. Properties with values for just one material (10, in this case) are not shown.
For each property being compared, the top bar is SAE-AISI 4340M steel and the bottom bar is S31727 stainless steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 710 | |
| 190 |
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 200 |
| Elongation at Break, % | 6.0 | |
| 40 |
| Fatigue Strength, MPa | 690 | |
| 240 |
| Poisson's Ratio | 0.29 | |
| 0.28 |
| Shear Modulus, GPa | 72 | |
| 78 |
| Shear Strength, MPa | 1360 | |
| 430 |
| Tensile Strength: Ultimate (UTS), MPa | 2340 | |
| 630 |
| Tensile Strength: Yield (Proof), MPa | 1240 | |
| 270 |
Thermal Properties
| Latent Heat of Fusion, J/g | 280 | |
| 290 |
| Maximum Temperature: Mechanical, °C | 430 | |
| 1010 |
| Melting Completion (Liquidus), °C | 1440 | |
| 1440 |
| Melting Onset (Solidus), °C | 1400 | |
| 1390 |
| Specific Heat Capacity, J/kg-K | 480 | |
| 470 |
| Thermal Expansion, µm/m-K | 13 | |
| 16 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 3.9 | |
| 24 |
| Density, g/cm3 | 7.8 | |
| 8.0 |
| Embodied Carbon, kg CO2/kg material | 1.9 | |
| 4.7 |
| Embodied Energy, MJ/kg | 26 | |
| 64 |
| Embodied Water, L/kg | 55 | |
| 180 |
Common Calculations
| PREN (Pitting Resistance) | 2.2 | |
| 35 |
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 120 | |
| 200 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 4120 | |
| 190 |
| Stiffness to Weight: Axial, points | 13 | |
| 14 |
| Stiffness to Weight: Bending, points | 25 | |
| 24 |
| Strength to Weight: Axial, points | 84 | |
| 22 |
| Strength to Weight: Bending, points | 51 | |
| 20 |
| Thermal Shock Resistance, points | 70 | |
| 14 |
Alloy Composition
| Carbon (C), % | 0.38 to 0.43 | |
| 0 to 0.030 |
| Chromium (Cr), % | 0.7 to 1.0 | |
| 17.5 to 19 |
| Copper (Cu), % | 0 | |
| 2.8 to 4.0 |
| Iron (Fe), % | 93.3 to 94.8 | |
| 53.7 to 61.3 |
| Manganese (Mn), % | 0.65 to 0.9 | |
| 0 to 1.0 |
| Molybdenum (Mo), % | 0.35 to 0.45 | |
| 3.8 to 4.5 |
| Nickel (Ni), % | 1.7 to 2.0 | |
| 14.5 to 16.5 |
| Nitrogen (N), % | 0 | |
| 0.15 to 0.21 |
| Phosphorus (P), % | 0 to 0.012 | |
| 0 to 0.030 |
| Silicon (Si), % | 1.5 to 1.8 | |
| 0 to 1.0 |
| Sulfur (S), % | 0 to 0.012 | |
| 0 to 0.030 |
| Vanadium (V), % | 0.050 to 0.1 | |
| 0 |