EN 1.8509 Steel vs. EN 1.8550 Steel
Both EN 1.8509 steel and EN 1.8550 steel are iron alloys. Both are furnished in the quenched and tempered condition. Their average alloy composition is basically identical.
For each property being compared, the top bar is EN 1.8509 steel and the bottom bar is EN 1.8550 steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 340 | |
| 300 |
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 190 |
| Elongation at Break, % | 11 | |
| 11 |
| Fatigue Strength, MPa | 580 | |
| 470 |
| Impact Strength: V-Notched Charpy, J | 29 | |
| 34 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Shear Modulus, GPa | 73 | |
| 73 |
| Shear Strength, MPa | 680 | |
| 600 |
| Tensile Strength: Ultimate (UTS), MPa | 1130 | |
| 1000 |
| Tensile Strength: Yield (Proof), MPa | 940 | |
| 760 |
Thermal Properties
| Latent Heat of Fusion, J/g | 250 | |
| 250 |
| Maximum Temperature: Mechanical, °C | 440 | |
| 440 |
| Melting Completion (Liquidus), °C | 1450 | |
| 1450 |
| Melting Onset (Solidus), °C | 1410 | |
| 1410 |
| Specific Heat Capacity, J/kg-K | 480 | |
| 480 |
| Thermal Conductivity, W/m-K | 39 | |
| 40 |
| Thermal Expansion, µm/m-K | 13 | |
| 13 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 7.5 | |
| 7.6 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 8.6 | |
| 8.8 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 2.8 | |
| 3.4 |
| Density, g/cm3 | 7.8 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 1.6 | |
| 1.7 |
| Embodied Energy, MJ/kg | 22 | |
| 23 |
| Embodied Water, L/kg | 65 | |
| 67 |
Common Calculations
| PREN (Pitting Resistance) | 2.6 | |
| 2.3 |
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 120 | |
| 100 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 2340 | |
| 1550 |
| Stiffness to Weight: Axial, points | 13 | |
| 13 |
| Stiffness to Weight: Bending, points | 25 | |
| 24 |
| Strength to Weight: Axial, points | 40 | |
| 36 |
| Strength to Weight: Bending, points | 31 | |
| 29 |
| Thermal Diffusivity, mm2/s | 10 | |
| 11 |
| Thermal Shock Resistance, points | 33 | |
| 29 |
Alloy Composition
| Aluminum (Al), % | 0.8 to 1.2 | |
| 0.8 to 1.2 |
| Carbon (C), % | 0.38 to 0.45 | |
| 0.3 to 0.37 |
| Chromium (Cr), % | 1.5 to 1.8 | |
| 1.5 to 1.8 |
| Iron (Fe), % | 95.5 to 97.1 | |
| 94.4 to 96.3 |
| Manganese (Mn), % | 0.4 to 0.7 | |
| 0.4 to 0.7 |
| Molybdenum (Mo), % | 0.2 to 0.35 | |
| 0.15 to 0.25 |
| Nickel (Ni), % | 0 | |
| 0.85 to 1.2 |
| Phosphorus (P), % | 0 to 0.025 | |
| 0 to 0.025 |
| Silicon (Si), % | 0 to 0.4 | |
| 0 to 0.4 |
| Sulfur (S), % | 0 to 0.035 | |
| 0 to 0.035 |