Description of AISI 4340 Alloy Steel Round Bar
AISI/SAE 4340 is a chromium‐alloyed steel grade that is extensively used in the oil and gas industry. It exhibits a high tensile strength and responds suitably to heat treatment, thereby achieving a measured balance between ductility and strength when treated.

Specification of AISI 4340 Alloy Steel Round Bar
Element
|
Content (%)
|
Iron, Fe
|
95.195 - 96.33
|
Nickel, Ni
|
1.65 - 2.00
|
Chromium, Cr
|
0.700 - 0.900
|
Manganese, Mn
|
0.600 - 0.800
|
Carbon, C
|
0.370 - 0.430
|
Molybdenum, Mo
|
0.200 - 0.300
|
Silicon, Si
|
0.150 - 0.300
|
Sulphur, S
|
0.0400
|
Phosphorus, P
|
0.0350
|
Brinell Hardness
|
293 HB
|
Tensile Strength
|
1014 MPa
|
Elongation at Fracture
|
19 %
|
Reduction in Area
|
60.40 %
|
Elastic Modulus
|
200 GPa
|
Elastic Modulus
|
159 GPa
|
Poisson's Ratio
|
29 %
|
Machinability
|
50 %
|
Shear Modulus
|
78 GPa
|
Density
|
7,85 g/cm3
|
Melting Point
|
1427 °C
|
Specifications: ASTM A 829 / A6 SAE J404, AMS 2252/ 2301/6359 SAE J404
Applications of AISI 4340 Alloy Steel Round Bar
- Aircraft Undercarriage Components:
- Given its high tensile strength, it is employed in the production of aircraft undercarriage parts, including struts and connecting rods.
- Components for Vehicle Transmissions:
- It is used in automotive systems, particularly for the manufacturing of transmission components such as gears and shafts, thereby contributing to consistent performance.
- Forged Hydraulic Components:
- It is employed in the forging of hydraulic device parts, where its mechanical properties provide reliable performance under pressure.
- Crankshafts Made from High-Strength Forged Steel:
- It is used in the production of engine crankshafts, where high strength and fatigue resistance are required for efficient operation.
- Gears and Shafts for Power Transmission:
- They are manufactured for power transmission systems, offering wear resistance and toughness for industrial applications.
Packaging:
Our alloy steel AISI 4340 is handled carefully during storage and transport in order to preserve the quality of our product in its original state.