Introduction
Alloy steels comprise a wide range of steels whose compositions are more than the limitations of C, Mo, Cr, Va, Mn, Ni, Si, and B which have been fixed for carbon steels. These steels are more responsive to mechanical and heat treatments than carbon steels.
The following datasheet will provide details about AISI 5140 alloy steel.
Chemical Composition
The following table shows the chemical composition of AISI 5140 alloy steel.
| Element | Content (%) |
|---|---|
| Iron, Fe | 97.395-98.07 |
| Manganese, Mn | 0.700-0.900 |
| Chromium, Cr | 0.700-0.900 |
| Carbon, C | 0.380-0.430 |
| Silicon, Si | 0.150-0.300 |
| Sulfur, S | ≤ 0.0400 |
| Phosphorous, P | ≤ 0.0350 |
Physical Properties
The physical properties of AISI 5140 alloy steel are outlined in the following table.
| Properties | Metric | Imperial |
|---|---|---|
| Density | 7.85 g/cm3 | 0.284 lb/in³ |
Mechanical Properties
The mechanical properties of annealed AISI 5140 alloy steel are highlighted in the table below.
| Properties | Metric | Imperial |
|---|---|---|
| Tensile strength | 570 MPa | 82700 psi |
| Yield strength | 295 MPa | 42800 psi |
| Elastic modulus | 190-210 GPa | 27557-30458 ksi |
| Bulk modulus (typical for steel) | 140 GPa | 20300 ksi |
| Shear modulus (typical for steel) | 80 GPa | 11600 ksi |
| Poisson’s ratio | 0.27-0.30 | 0.27-0.30 |
| Izod Impact | 41.0 J | 30.2 ft.lb |
| Hardness, Brinell | 167 | 167 |
| Hardness, Knoop (converted from Brinell hardness) | 188 | 188 |
| Hardness, Rockwell B (converted from Brinell hardness) | 85 | 85 |
| Hardness, Vickers (converted from Brinell hardness) | 175 | 175 |
| Machinability (annealed and cold drawn, based on 100 machinability for AISI 1212 steel) | 65 | 65 |
Thermal Properties
The thermal properties of AISI 5140 alloy steel are provided in the table below.
| Properties | Metric | Imperial |
|---|---|---|
| Thermal conductivity | 44.6 W/mK | 310 BTU in/hr.ft².°F |
| Thermal expansion co-efficient (@20-200°C/68-392°F) | 12.6 µm/m°C | 7 µin/in°F |
Other Designations
Equivalent materials to AISI 5140 alloy steel are as follows.
| AISI 5140 | AFNOR 42 C 4 | DIN 1.7035 | UNI 40 Cr 4 | UNI 41 Cr 4 KB | JIS SCr 4 H |
| B.S. 2 S 117 | B.S. 530 A 40 | B.S. 530 H 40 | B.S. 530 M 40 | ASTM A322 | ASTM A331 |
| ASTM A505 | ASTM A519 | SAE J404 | SAE J412 | SAE J770 | AFNOR 42 C 2 |