SAE-AISI 8740 Steel vs. R05255 Alloy
SAE-AISI 8740 steel belongs to the iron alloys classification, while R05255 alloy belongs to the otherwise unclassified metals. There are 20 material properties with values for both materials. Properties with values for just one material (11, in this case) are not shown. Please note that the two materials have significantly dissimilar densities. This means that additional care is required when interpreting the data, because some material properties are based on units of mass, while others are based on units of area or volume.
For each property being compared, the top bar is SAE-AISI 8740 steel and the bottom bar is R05255 alloy.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 190 |
| Elongation at Break, % | 11 to 23 | |
| 20 |
| Poisson's Ratio | 0.29 | |
| 0.34 |
| Shear Modulus, GPa | 73 | |
| 70 |
| Tensile Strength: Ultimate (UTS), MPa | 580 to 670 | |
| 540 |
| Tensile Strength: Yield (Proof), MPa | 380 to 570 | |
| 450 |
Thermal Properties
| Latent Heat of Fusion, J/g | 250 | |
| 140 |
| Specific Heat Capacity, J/kg-K | 470 | |
| 140 |
| Thermal Conductivity, W/m-K | 39 | |
| 59 |
| Thermal Expansion, µm/m-K | 13 | |
| 6.6 |
Otherwise Unclassified Properties
| Density, g/cm3 | 7.8 | |
| 17 |
| Embodied Water, L/kg | 50 | |
| 630 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 71 to 120 | |
| 100 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 390 to 850 | |
| 530 |
| Stiffness to Weight: Axial, points | 13 | |
| 6.3 |
| Stiffness to Weight: Bending, points | 24 | |
| 11 |
| Strength to Weight: Axial, points | 20 to 24 | |
| 9.1 |
| Strength to Weight: Bending, points | 20 to 22 | |
| 8.9 |
| Thermal Diffusivity, mm2/s | 10 | |
| 25 |
| Thermal Shock Resistance, points | 17 to 20 | |
| 31 |
Alloy Composition
| Carbon (C), % | 0.38 to 0.43 | |
| 0 to 0.010 |
| Chromium (Cr), % | 0.4 to 0.6 | |
| 0 |
| Hydrogen (H), % | 0 | |
| 0 to 0.0015 |
| Iron (Fe), % | 96.5 to 97.7 | |
| 0 to 0.010 |
| Manganese (Mn), % | 0.75 to 1.0 | |
| 0 |
| Molybdenum (Mo), % | 0.2 to 0.3 | |
| 0 to 0.020 |
| Nickel (Ni), % | 0.4 to 0.7 | |
| 0 to 0.010 |
| Niobium (Nb), % | 0 | |
| 0 to 0.5 |
| Nitrogen (N), % | 0 | |
| 0 to 0.010 |
| Oxygen (O), % | 0 | |
| 0 to 0.015 |
| Phosphorus (P), % | 0 to 0.035 | |
| 0 |
| Silicon (Si), % | 0.15 to 0.35 | |
| 0 to 0.0050 |
| Sulfur (S), % | 0 to 0.040 | |
| 0 |
| Tantalum (Ta), % | 0 | |
| 95.9 to 98 |
| Titanium (Ti), % | 0 | |
| 0 to 0.010 |
| Tungsten (W), % | 0 | |
| 2.0 to 3.5 |