Description of AISI 4340 Alloy Flat Bar Steel
AISI 4340 is a Nickel-Chromium-Molybdenum alloyed steel with high tensile strength. It responds well to oil heat treatment and exhibits a measured combination of ductility and strength when treated accordingly. It is used in civil and military aviation, in the automotive industry and for forged hydraulic as well as other machine tool applications.

Specification of AISI 4340 Alloy Flat Bar Steel
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
|
1 014 MPa
|
Elongation at Break
|
19 %
|
Reduction of 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
|
1 427 °C
|
Specifications: ASTM A 829 / A6 SAE J404, AMS 2252/ 2301/6359 SAE J404
Applications of AISI 4340 Alloy Flat Bar Steel
- Aircraft landing gear components:
- It is used in the manufacture of aircraft landing gear components, including struts and connecting rods, as indicated by its tensile strength of 1 014 MPa.
- Components for vehicle transmissions:
- It is applied in automotive systems, particularly in the production of transmission components such as gears and shafts. Its measured properties meet the performance requirements.
- Forged hydraulic equipment:
- It is used in forging hydraulic components. Its measured strength and impact resistance support operation under pressure.
- Crankshafts from high‐strength forged steel:
- It is utilised in the manufacture of crankshafts for engines, which require specific tensile strength and fatigue resistance for efficient performance.
- Gears and shafts for power transmission:
- They are used in the manufacture of gears and shafts for power transmission systems. Their wear resistance and toughness satisfy the technical demands of industrial applications.
Packaging:
Our alloyed steel AISI 4340 is managed during storage and transport in a manner that maintains its original condition.