ThePipingMart Blog Grades AMS 6415 Alloy Steel – Composition, Properties, and Uses

AMS 6415 Alloy Steel – Composition, Properties, and Uses

AMS 6415

If you are in the engineering or manufacturing industry, you have probably heard of AISI 4340 or SAE 4340. However, have you ever heard of AMS 6415? This high-strength, low-alloy steel is a lesser-known material with much to offer regarding various applications. This blog post will explore the composition, physical and mechanical properties, uses hardness, and heat treatment of AMS 6415.

What is AMS 6415?

AMS 6415 (also known as SAE – AISI 4340 Alloy Steel) is a steel that is low alloy steel that is commonly used in the construction of aircraft and other high-stress applications. Its superior strength and durability set it apart from other steel types, making it a popular choice for industries that require materials that can withstand harsh conditions. SAE – AMS 6415 metal is also known for its exceptional resistance to wear, making it suitable for use in parts that experience a lot of stress or friction. Despite its tough nature, it is still relatively easy to machine and weld, making it flexible and easy to work with. Overall, AMS6415 metal is a versatile and reliable material many industries trust for its impressive properties.

What Form is AMS 6415 Available at Piping Mart?

  • Alloy Steel AISI 4340 Bars

AMS 6415  Composition

AMS 6415 sheet is a low-alloy steel composed of iron, carbon, manganese, chromium, molybdenum, nickel, and copper. Its chemical composition includes 0.14–0.22% carbon, 0.7–1.0% manganese, 0.4–0.6% chromium, 0.15–0.25% molybdenum, 1.35–1.65% nickel, and 0.18–0.23% copper. This composition provides AMS6415 with excellent toughness, hardenability, and resistance to wear and fatigue.

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
Sulfur, S  0.0400
Phosphorous, P  0.0350

AMS 6415 Physical Properties

AMS 6415 has a density of 7.85 g/cm3, a melting point of 1399°C, and a thermal conductivity of 39.3 W/m.K. Regarding its electrical conductivity, AMS 6415 is not an ideal conductor since its electrical resistivity is 1450 nΩ·m. However, its thermal expansion coefficient is 11.50 µm/m·K, which is desirable in high-temperature applications.

Properties Metric Imperial
Density 7.85 g/cm3 0.284 lb/in³
Melting point 1427°C 2600°F

AMS 6415 Mechanical Properties

AMS 6415 steel tubes is well-known for its high strength, excellent fatigue resistance, and toughness. Its tensile strength ranges from 1080–1340 MPa, while its yield strength is 930 MPa. Its elongation rate is 12%, which signifies its ability to resist fracture due to sudden impact. Additionally, it has good corrosion resistance in oil and gas environments, making it ideal for high-pressure pipelines, drill collars and valve components.

Properties Metric Imperial
Tensile strength 745 MPa 108000 psi
Yield strength 470 MPa 68200 psi
Bulk modulus (typical for steel) 140 GPa 20300 ksi
Shear modulus (typical for steel) 80 GPa 11600 ksi
Elastic modulus 190-210 GPa 27557-30458 ksi
Poisson’s ratio 0.27-0.30 0.27-0.30
Elongation at break 22% 22%
Reduction of area 50% 50%
Hardness, Brinell 217 217
Hardness, Knoop (converted from Brinell hardness) 240 240
Hardness, Rockwell B (converted from Brinell hardness) 95 95
Hardness, Rockwell C (converted from Brinell hardness. Value below normal HRC range, for comparison purposes only) 17 17
Hardness, Vickers (converted from Brinell hardness) 228 228
Machinability (annealed and cold drawn. Based on 100 machinability for AISI 1212 steel.) 50 50

AMS 6415 Equivalents

AMS 6359 AMS 6454 ASTM A331 (4340) ASTM A711 SAE J1397 (4340)
AMS 6409 ASTM A29 (4340) ASTM A506 (4340) ASTM A752 (4340) SAE J404 (4340)
AMS 6414 ASTM A320 (L43) ASTM A519 (4340) ASTM A829 SAE J412 (4340)
AMS 6415 ASTM A322 (4340) ASTM A646 (4340-7) MIL S-5000

AMS 6415 Specifications

Country USA Britain Britain Japan
Standard ASTM A29 EN 10250 BS 970 JIS G4103
Grades 4340 36CrNiMo4/
EN24/817M40 SNCM 439/SNCM8

AMS 6415 Uses

AMS 6415 material’s unique combination of properties makes it ideal for various high-stress engineering applications. It is commonly used to manufacture aircraft landing gears, engine components, drive shafts, heavy-duty studs, and bolts. It is also suitable for producing machines that undergo extreme conditions, such as mining, construction, and drilling equipment.

AMS 6415 Hardness

AMS 6415 has a hardness range of 248–302 HBW (Brinell Hardness), higher than most carbon steels. This property can be attributed to its various alloying elements, including molybdenum, nickel, and copper, contributing to its high hardness, wear resistance, and toughness.

AMS 6415 Heat Treatment

To achieve optimum mechanical properties, AMS 6415 materials undergoes various heat treatment processes such as annealing, normalizing, and tempering. Annealing is heating the material until it reaches its critical temperature and cooling it slowly to soften the metal. Normalizing, however, involves heating the material to a specific temperature and cooling it in the air. Tempering is heating the material to a particular temperature and then cooling it in water or oil to achieve the desired hardness.


In conclusion, AMS 6415 material is a lesser-known, high-strength, low-alloy steel ideal for various high-stress engineering applications. Its unique combination of properties, including toughness, excellent fatigue, and wear resistance, make it suitable for producing aircraft landing gears, engine components, drive shafts, drill collars, and high-pressure pipelines. It can also undergo heat treatment processes such as annealing, normalizing, and tempering to achieve optimum mechanical properties. With its outstanding properties, AMS 6415 is an excellent choice for any engineer or manufacturer needing high-performance material for their application.

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