SAE-AISI 8645 Steel vs. AISI 321 Stainless Steel
Both SAE-AISI 8645 steel and AISI 321 stainless steel are iron alloys. They have 72% of their average alloy composition in common. There are 31 material properties with values for both materials. Properties with values for just one material (2, in this case) are not shown.
For each property being compared, the top bar is SAE-AISI 8645 steel and the bottom bar is AISI 321 stainless steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 180 to 200 | |
| 170 to 210 |
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 200 |
| Elongation at Break, % | 12 to 23 | |
| 34 to 50 |
| Fatigue Strength, MPa | 280 to 350 | |
| 220 to 270 |
| Poisson's Ratio | 0.29 | |
| 0.28 |
| Shear Modulus, GPa | 73 | |
| 77 |
| Shear Strength, MPa | 380 to 400 | |
| 420 to 460 |
| Tensile Strength: Ultimate (UTS), MPa | 600 to 670 | |
| 590 to 690 |
| Tensile Strength: Yield (Proof), MPa | 390 to 560 | |
| 220 to 350 |
Thermal Properties
| Latent Heat of Fusion, J/g | 250 | |
| 290 |
| Maximum Temperature: Mechanical, °C | 410 | |
| 870 |
| Melting Completion (Liquidus), °C | 1460 | |
| 1430 |
| Melting Onset (Solidus), °C | 1420 | |
| 1400 |
| Specific Heat Capacity, J/kg-K | 470 | |
| 480 |
| Thermal Conductivity, W/m-K | 39 | |
| 16 |
| Thermal Expansion, µm/m-K | 13 | |
| 17 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 7.3 | |
| 2.4 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 8.4 | |
| 2.7 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 2.6 | |
| 16 |
| Density, g/cm3 | 7.8 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 1.5 | |
| 3.2 |
| Embodied Energy, MJ/kg | 20 | |
| 45 |
| Embodied Water, L/kg | 50 | |
| 140 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 77 to 120 | |
| 190 to 230 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 420 to 840 | |
| 130 to 310 |
| Stiffness to Weight: Axial, points | 13 | |
| 14 |
| Stiffness to Weight: Bending, points | 24 | |
| 25 |
| Strength to Weight: Axial, points | 21 to 24 | |
| 21 to 25 |
| Strength to Weight: Bending, points | 20 to 22 | |
| 20 to 22 |
| Thermal Diffusivity, mm2/s | 10 | |
| 4.1 |
| Thermal Shock Resistance, points | 18 to 20 | |
| 13 to 15 |
Alloy Composition
| Carbon (C), % | 0.43 to 0.48 | |
| 0 to 0.080 |
| Chromium (Cr), % | 0.4 to 0.6 | |
| 17 to 19 |
| Iron (Fe), % | 96.5 to 97.7 | |
| 65.3 to 74 |
| Manganese (Mn), % | 0.75 to 1.0 | |
| 0 to 2.0 |
| Molybdenum (Mo), % | 0.15 to 0.25 | |
| 0 |
| Nickel (Ni), % | 0.4 to 0.7 | |
| 9.0 to 12 |
| Nitrogen (N), % | 0 | |
| 0 to 0.1 |
| Phosphorus (P), % | 0 to 0.035 | |
| 0 to 0.045 |
| Silicon (Si), % | 0.15 to 0.35 | |
| 0 to 0.75 |
| Sulfur (S), % | 0 to 0.040 | |
| 0 to 0.030 |
| Titanium (Ti), % | 0 | |
| 0 to 0.7 |