About Alloy
4340 steel is a high-performance alloy steel known for its exceptional mechanical properties, making it suitable for a wide range of demanding applications. This steel is characterized by its carefully balanced composition of carbon, chromium, nickel, and molybdenum, which collectively contribute to its impressive strength, toughness, and hardenability. The alloy contains approximately 0.38 to 0.43% carbon, which provides a good foundation for achieving high tensile strength and hardness. Chromium (0.70 - 0.90%) and nickel (1.65 - 2.00%) enhance the steel's overall strength and toughness, while molybdenum (0.20 - 0.30%) improves its hardenability and resistance to wear.
One of the key attributes of 4340 steel is its high tensile strength, which can be significantly enhanced through heat treatment processes such as quenching and tempering. This steel can achieve tensile strengths of up to 1,100 MPa (160,000 psi), making it ideal for applications that require materials to withstand high stress and load. Additionally, 4340 steel boasts excellent toughness and impact resistance, which makes it highly durable and reliable in harsh operating environments. This is particularly important in applications where components are subjected to cyclic loading or sudden impacts.
Despite its many advantages, 4340 steel does have some limitations. Its higher alloy content and the complexity of the heat treatment process can make it more expensive compared to other steels. Furthermore, while 4340 steel offers excellent strength and toughness, it can be challenging to machine, requiring specialized tools and techniques to achieve desired tolerances and finishes. Overall, 4340 steel remains a highly valuable material in engineering and manufacturing due to its exceptional balance of strength, toughness, and durability, making it well-suited for high-performance and critical applications across a range of industries.
Product Form & Standard
AMS 6359 Sheet / strip / plate
AMS 6409 Bars / Forgings N&T
AMS 6414 Vac Melt Bars / Forgings
AMS 6415 Bars / Forgings
AMS 6484 Bars / Forgings N&T
Chemical Composition
| Weight% | C | Mn | P & S | Si | Cr | Ni | Mo |
| E4340 Bar | 0.38 - 0.43 | 0.65 - 0.85 | 0.025 | 0.15-0.30 | 0.70-0.90 | 1.65-2.00 | 0.20-0.30 |
| E4340 Plate | 0.38-0.43 | 0.60-0.80 | 0.025 | 0.15-0.35 | 0.70-0.90 | 1.65-2.00 | 0.20-0.30 |
Mechanical Properties
| Alloy | Condition | Tensile Strength ksi | Yield Strength ksi | Elongation 4D % | Reduction of Area % | Hardness HB |
| E4340 Bar | Annealed | - | - | - | - | 235 max |
| E4340 Bar | Hardened and Tempered | 260 | 217 | 10 | 30 | - |
Application
1. Automotive Industry
●Components: Crankshafts, camshafts, and gears.
●Benefits: High strength and toughness enhance performance and durability.
2. Aerospace Industry
●Components: Landing gear, turbine shafts, and structural parts.
●Benefits: Excellent mechanical properties ensure safety and reliability in high-performance applications.
3. Military and Defense
●Components: Weapon systems and armored vehicles.
●Benefits: High impact resistance and toughness are critical for defense applications.
4. Industrial Equipment
●Components: Gears, bearings, and shafts.
●Benefits: Durability and wear resistance for heavy-duty machinery.
5. Oil and Gas Industry
●Components: Drilling equipment and valve bodies.
●Benefits: Strength and resistance to wear handle harsh conditions.
6. Mining Industry
●Components: Mining equipment such as crushers and drills.
●Benefits: Toughness and wear resistance for demanding environments.
7. Power Generation
●Components: Turbine shafts.
●Benefits: Strength and resistance to high temperatures for reliable power generation.
8. High-Performance Sporting Equipment
●Components: High-end sporting gear.
●Benefits: Strength and impact resistance enhance performance.
Your enquiry
Can't find the information you need? Please contact us directly.