SAE-AISI 5145 Steel vs. SAE-AISI 4340 Steel
Both SAE-AISI 5145 steel and SAE-AISI 4340 steel are iron alloys. They have a very high 98% of their average alloy composition in common.
For each property being compared, the top bar is SAE-AISI 5145 steel and the bottom bar is SAE-AISI 4340 steel.
Metric UnitsUS Customary Units
Mechanical Properties
Brinell Hardness | 170 | |
210 to 360 |
Elastic (Young's, Tensile) Modulus, GPa | 190 | |
190 |
Elongation at Break, % | 20 | |
12 to 22 |
Fatigue Strength, MPa | 250 | |
330 to 740 |
Poisson's Ratio | 0.29 | |
0.29 |
Shear Modulus, GPa | 73 | |
73 |
Shear Strength, MPa | 350 | |
430 to 770 |
Tensile Strength: Ultimate (UTS), MPa | 560 | |
690 to 1280 |
Tensile Strength: Yield (Proof), MPa | 370 | |
470 to 1150 |
Thermal Properties
Latent Heat of Fusion, J/g | 250 | |
250 |
Maximum Temperature: Mechanical, °C | 420 | |
430 |
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 | 47 | |
44 |
Thermal Expansion, µm/m-K | 12 | |
13 |
Electrical Properties
Electrical Conductivity: Equal Volume, % IACS | 7.2 | |
7.5 |
Electrical Conductivity: Equal Weight (Specific), % IACS | 8.3 | |
8.6 |
Otherwise Unclassified Properties
Base Metal Price, % relative | 2.1 | |
3.5 |
Density, g/cm3 | 7.8 | |
7.8 |
Embodied Carbon, kg CO2/kg material | 1.4 | |
1.7 |
Embodied Energy, MJ/kg | 19 | |
22 |
Embodied Water, L/kg | 49 | |
53 |
Common Calculations
Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 100 | |
79 to 170 |
Resilience: Unit (Modulus of Resilience), kJ/m3 | 360 | |
590 to 3490 |
Stiffness to Weight: Axial, points | 13 | |
13 |
Stiffness to Weight: Bending, points | 24 | |
24 |
Strength to Weight: Axial, points | 20 | |
24 to 45 |
Strength to Weight: Bending, points | 19 | |
22 to 33 |
Thermal Diffusivity, mm2/s | 13 | |
12 |
Thermal Shock Resistance, points | 17 | |
20 to 38 |
Alloy Composition
Carbon (C), % | 0.43 to 0.48 | |
0.38 to 0.43 |
Chromium (Cr), % | 0.7 to 0.9 | |
0.7 to 0.9 |
Iron (Fe), % | 97.3 to 98 | |
95.1 to 96.3 |
Manganese (Mn), % | 0.7 to 0.9 | |
0.6 to 0.8 |
Molybdenum (Mo), % | 0 | |
0.2 to 0.3 |
Nickel (Ni), % | 0 | |
1.7 to 2.0 |
Phosphorus (P), % | 0 to 0.035 | |
0 to 0.035 |
Silicon (Si), % | 0.15 to 0.35 | |
0.15 to 0.35 |
Sulfur (S), % | 0 to 0.040 | |
0 to 0.040 |