EN 1.7725 Steel vs. EN 1.7720 Steel
Both EN 1.7725 steel and EN 1.7720 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 EN 1.7725 steel and the bottom bar is EN 1.7720 steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 250 to 300 | |
| 180 |
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 190 |
| Elongation at Break, % | 14 | |
| 19 |
| Fatigue Strength, MPa | 390 to 550 | |
| 230 |
| Impact Strength: V-Notched Charpy, J | 34 to 35 | |
| 30 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Shear Modulus, GPa | 73 | |
| 73 |
| Tensile Strength: Ultimate (UTS), MPa | 830 to 1000 | |
| 590 |
| Tensile Strength: Yield (Proof), MPa | 610 to 860 | |
| 340 |
Thermal Properties
| Latent Heat of Fusion, J/g | 250 | |
| 250 |
| Maximum Temperature: Mechanical, °C | 440 | |
| 410 |
| Melting Completion (Liquidus), °C | 1460 | |
| 1470 |
| Melting Onset (Solidus), °C | 1420 | |
| 1430 |
| Specific Heat Capacity, J/kg-K | 470 | |
| 470 |
| Thermal Conductivity, W/m-K | 39 | |
| 40 |
| Thermal Expansion, µm/m-K | 13 | |
| 13 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 7.4 | |
| 7.3 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 8.6 | |
| 8.4 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 2.9 | |
| 2.8 |
| Density, g/cm3 | 7.8 | |
| 7.9 |
| Embodied Carbon, kg CO2/kg material | 1.8 | |
| 2.2 |
| Embodied Energy, MJ/kg | 24 | |
| 30 |
| Embodied Water, L/kg | 54 | |
| 51 |
Common Calculations
| PREN (Pitting Resistance) | 2.8 | |
| 2.1 |
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 110 to 130 | |
| 97 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 980 to 1940 | |
| 300 |
| Stiffness to Weight: Axial, points | 13 | |
| 13 |
| Stiffness to Weight: Bending, points | 24 | |
| 24 |
| Strength to Weight: Axial, points | 29 to 35 | |
| 21 |
| Strength to Weight: Bending, points | 25 to 28 | |
| 20 |
| Thermal Diffusivity, mm2/s | 11 | |
| 11 |
| Thermal Shock Resistance, points | 24 to 29 | |
| 17 |
Alloy Composition
| Carbon (C), % | 0.27 to 0.34 | |
| 0.1 to 0.15 |
| Chromium (Cr), % | 1.3 to 1.7 | |
| 0.3 to 0.5 |
| Copper (Cu), % | 0 | |
| 0 to 0.3 |
| Iron (Fe), % | 95.7 to 97.5 | |
| 96.6 to 98.6 |
| Manganese (Mn), % | 0.6 to 1.0 | |
| 0.4 to 0.7 |
| Molybdenum (Mo), % | 0.3 to 0.5 | |
| 0.4 to 0.6 |
| Nickel (Ni), % | 0 | |
| 0 to 0.4 |
| Phosphorus (P), % | 0 to 0.025 | |
| 0 to 0.030 |
| Silicon (Si), % | 0 to 0.6 | |
| 0 to 0.45 |
| Sulfur (S), % | 0 to 0.030 | |
| 0 to 0.020 |
| Vanadium (V), % | 0.050 to 0.15 | |
| 0.22 to 0.3 |