
Alloy steels are designated by AISI four-digit numbers and comprise different kinds of steels, each with a composition which exceeds the limitations of B, C, Mn, Mo, Ni, Si, Cr, and Va set for carbon steels. AISI 4140 alloy steel is a chromium-, molybdenum-, and manganese-containing low alloy steel. It has high fatigue strength, abrasion and impact resistance, toughness, and torsional strength.
| Element | Content(%) |
|---|---|
| Chromium, Cr | 0.80 - 1.10 |
| Manganese, Mn | 0.75 - 1.0 |
| Carbon, C | 0.380 - 0.430 |
| Silicon, Si | 0.15 - 0.30 |
| Molybdenum, Mo | 0.15 - 0.25 |
| Sulfur, S | 0.040 |
| Phosphorous, P | 0.035 |
| Iron, Fe | Balance |
| 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 |
| Production Route | Hot Rolled, Cold Rolled |
| Material Standard | AISI, ASTM, ASME, DIN, BS, EN, ISO, JIS, GOST, SAE, IS & Custom Chemistry |
| Size | Width from 100mm to 3000mm ; Length from 500mm to 12000mm |
| Thickness | 0.1mm to 400mm |
| Delivery Condition | As Rolled, Annealed, Quenched and Tempered, Normalized |
| Surface Finish | Plain, Brushed, Cladded |