ThePipingMart Blog Grades AMS 4340 Aluminum Alloy – Composition, Properties, and Uses

AMS 4340 Aluminum Alloy – Composition, Properties, and Uses

AMS 4340

AMS 4340 material is a popular grade of alloy steel that is widely used in various industries for its exceptional mechanical properties. This high-strength steel exhibits excellent toughness, ductility, and wear resistance, making it an ideal material for critical applications that demand superior mechanical performance. This blog post will look closer at AMS4340 and discuss its composition, physical and mechanical properties, and uses.

What is AMS 4340?

AMS 4340 (also known as 7050 Aluminium Alloy) is a type of steel alloy that is highly sought after in many industrial applications. With a unique blend of strength and durability, it is used in everything from aircraft engines to heavy construction equipment. What sets this particular alloy apart is its ability to withstand extreme temperatures and resist corrosion even under the harshest conditions. Its versatility and reliability make it a popular choice among engineers and manufacturers requiring top-quality materials. Whether you are in the aerospace or automotive industry or need a durable material for your next project, AMS4340 is worth considering.

What Form is AMS 4340 Available at Piping Mart?

  • Pipes
  • Tubing

AMS 4340 Composition

AMS 4340 sheet is a low-alloy steel that includes the following elements: carbon, manganese, silicon, nickel, chromium, molybdenum, and vanadium. These elements work together to provide exceptional strength, toughness, and resistance to corrosion, fatigue, and wear. The precise composition of AMS 4340 pipes varies depending on the specific application requirements, but typical values are carbon (0.38-0.43%), manganese (0.60-0.80%), silicon (0.15-0.35%), nickel (1.65-2.00%), chromium (0.70-0.90%), molybdenum (0.20-0.30%), and vanadium (0.8-1.10%).

Element Content (%)
Aluminum, Al 87.3 – 90.3
Zinc, Z 5.7 – 6.7
Copper, Cu 2.0 – 2.6
Magnesium, Mg 1.9 – 2.6
Zirconium, Zr 0.08 – 0.15
Iron, Fe ≤ 0.15
Silicon, Si ≤ 0.12
Mangnese, Mn ≤ 0.10
Titanium, Ti ≤ 0.06
Chromium, Cr ≤ 0.04

AMS 4340 Physical Properties

AMS 4340 tubes exhibits excellent physical properties that make it suitable for applications in extreme environments. It has a density of 7.85 g/cm³ and a melting point of 1415-1465°C. It also has a thermal conductivity of 41.9 W/m-K, which makes it an excellent thermal conductor. In addition, AMS 4340 has a low coefficient of thermal expansion, which means it can withstand significant temperature changes without experiencing thermal stress.

Property Metric Imperial
Density 2.6-2.8 g/cm3 0.0939-0.101 lb/in3
Melting Point 494°C 920°F

AMS 4340 Mechanical Properties

AMS 4340 exhibits exceptional mechanical properties, which makes it an ideal material for high-stress applications. Its tensile strength ranges from 1300-1500 MPa, while its yield strength ranges from 1050-1350 MPa. AMS 4340 also has a good balance of hardness and toughness and can be easily machined and welded. The steel’s elongation at break is typically around 12%, which indicates its outstanding ductility.

Property Metric Imperial
Hardness, Brinell 140 140
Hardness, Knoop 177 177
Hardness, Rockewell A 51.6 51.6
Hardness, Rockwell B 84 84
Hardness, Vickers 162 162
Ultimate Tensile Strength 524 MPa 76000 psi
Tensile Yield Strength 469 MPa 68000 psi
Elongation at Break 11% 11%
Modulus of Elasticity 71.6 GPa 10400 ksi
Poisson’s Ratio 0.33 0.33
Shear Modulus 26.9 GPa 3900 ksi
Shear Strength 303 MPa 44000 psi

AMS 4340 Equivalents

  • AMS 4108
  • AMS 4201
  • ASTM B247
  • ASTM B316
  • QQ A-430

AMS 4340 Specifications

  • AMS 4050: 7050-T7451 Plate
  • AMS 4107:7050-T74 Die Forging
  • AMS 4108:7050-T7452 Hand Forgings
  • AMS 4201: 7050-T7651 Plate
  • AMS 4333: 7050-T7452 Forgings
  • AMS 4340: 7050-T76511 Extrusions
  • AMS 4341: 7050-T73511 Extrusions
  • AMS 4342: 7050-T74511 Extrusions
  • ASTM B247
  • ASTM B316
  • QQ A-430
  • DMS-2233
  • BMS 7-323

AMS 4340 Uses

AMS 4340 is a versatile steel that finds applications across various industries. It is commonly used to manufacture gears, crankshafts, connecting rods, and other critical components that require high strength and toughness. This steel is also commonly used in the aerospace industry for its exceptional fatigue resistance and impact toughness. In addition, AMS 4340 is used in the oil and gas, power generation, and automotive industries.

AMS 4340 Hardness

AMS 4340 exhibits excellent hardness, which is essential for applications where wear resistance is critical. The steel can achieve a maximum surface hardness of 55 HRC through heat treatment, which involves quenching and tempering. This heat treatment process enhances the steel’s mechanical properties and improves its wear, fatigue, and corrosion resistance.

AMS 4340 Heat Treatment

Heat treatment is essential for improving the mechanical properties of AMS 4340. The steel is typically heated to 860-890°C and then quenched in oil or water to achieve maximum hardness. After quenching, the steel is tempered to relieve residual stress and improve its toughness. The tempering temperature typically ranges from 350 – 650°C, depending on the application requirements.


AMS 4340 is a high-strength steel with exceptional mechanical properties, making it an ideal material for critical applications. Its unique composition, physical and mechanical properties, and hardness make it an ideal material for manufacturing gears, crankshafts, connecting rods, and other critical components. Heat treatment is crucial in enhancing this steel’s mechanical properties and improving its resistance to wear, fatigue, and corrosion. Engineers must carefully consider AMS 4340’s material properties when designing components, as its unique characteristics provide an excellent combination of strength, toughness, and wear resistance, suitable for various extreme environments.

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