4140 is a 1% chromium – molybdenum medium harden capacity broadly useful in high tensile steel – for the most part supplied are hardened and tempered in the malleable scope of 850 – 1000 Mpa (condition T).4140 is presently accessible with enhanced mach inability, which greatly increases feeds and/or speeds, while also extending tool life without adversely affecting mechanical properties.
4140 is utilized broadly as a part of most industry areas for an extensive variety of utilizations, for example, Adapters, Arbors, Axle Shafts, Bolts, Crankshafts, Connection Rods, Chuck Bodies, Collets, Conveyor Pins & Rolls, Ejector Pins, Forks, Gears, Guide Rods, Hydraulic Shafts & Parts, Lathe Spindles, Logging Parts, Milling Spindles, Motor Shafts, Nuts, Pinch Bars, Pins Various, Pinions, Pump Shafts, Rams, Sockets, Spindles, Sprockets, Studs, Tool Holders, Torsion Bars, Worms etc.
| Element | Min | Max |
|---|---|---|
| Carbon, C | 0.35 | 0.45 |
| Manganese, Mn | 0.50 | 0.80 |
| Silicon, Si | 0.10 | 0.35 |
| Molybdenum, Mo | — | — |
| Chromium,Cr | 0.20 | 0.40 |
| Ni | 0.90 | 1.50 |
| Sulfur, S | — | 0.05 |
| Phosphorous, P | — | 0.05 |
| Properties | Metric | Imperial |
|---|---|---|
| Density | 7.85 g/cm³ | 0.284 lb/in³ |
| Melting Point | 1416°C | 2580°F |
| Properties | Metric | Imperial |
|---|---|---|
| Tensile Strength | 655 MPa | 95000 psi |
| Yield Strength | 415 MPa | 60200 psi |
| Bulk Modulus (typical for steel) | 140 GPa | 20300 ksi |
| Shear Modulus (typical for steel) | 80 GPa | 11600 ksi |
| Elastic Modulus | 190–210 GPa | 27557–30458 ksi |
| Poisson’s Ratio | 0.27–0.30 | 0.27–0.30 |
| Elongation at Break (in 50 mm) | 25.70% | 25.70% |
| Hardness, Brinell | 197 | 197 |
| Hardness, Knoop (converted from Brinell hardness) | 219 | 219 |
| Hardness, Rockwell B (converted from Brinell hardness) | 92 | 92 |
| Hardness, Rockwell C (converted from Brinell hardness. Value below normal HRC range, for comparison purposes only) | 13 | 13 |
| Hardness, Vickers (converted from Brinell hardness) | 207 | 207 |
| Machinability (based on AISI 1212 as 100 machinability) | 65 | 65 |
| Properties | Metric | Imperial |
|---|---|---|
| Thermal Expansion Co-efficient (@ 0-100°C / 32-212°F) | 12.2 µm/m°C | 6.78 µin/in°F |
| Thermal Conductivity | 42.6 W/mK | 296 BTU in/hr·ft²·°F |