ThePipingMart Blog Grades AMS 6322 Alloy Steel – Composition, Properties, and Uses

AMS 6322 Alloy Steel – Composition, Properties, and Uses

AMS 6322

When choosing a suitable metal for your project, you must consider several factors, including its composition and physical and mechanical properties. One of the popular metals in the market is AMS6322, known for its excellent hardness, strength, and versatility. Today’s blog post will explore the basic concepts of AMS 6322 and its uses, properties, and heat treatment.

What is AMS 6322?

AMS 6322 (also known as AISI 8740 Alloy Steel) is a high-performance steel alloy engineered to deliver enhanced strength, durability, and toughness for various applications. Under demanding conditions, this alloy is well-suited for critical components requiring superior performance, such as aerospace and defence applications. With its exceptional mechanical properties, AMS 6322 can withstand extreme temperatures, pressures, and loads while maintaining excellent resistance to wear, corrosion, and fatigue. Whether you are designing advanced aircraft, spacecraft, or ground-based equipment, AMS6322 can help you achieve your performance goals and deliver exceptional results in the most challenging environments.

AMS 6322 Composition

AMS6322 is a chromium-nickel-molybdenum steel alloy with a carbon content of 0.15%. It also contains small amounts of silicon, manganese, sulfur, and phosphorus. The alloy’s composition gives it excellent machinability and weldability, making it a popular choice in various industries.

Element Content (%)
Iron, Fe 96.595-97.72
Manganese, Mn 0.750-1.00
Nickel, Ni 0.400-0.700
Chromium, Cr 0.400-0.600
Carbon, C 0.380-0.430
Molybdenum, Mo 0.200-0.300
Silicon, Si 0.150-0.300
Sulfur, S 0.0400
Phosphorous, P 0.0350

AMS 6322 Physical Properties

AMS 6322 has a density of 7.85g/cm3 and a melting point of 1420-1465°C. The alloy has excellent resistance to corrosion and oxidation and is highly resistant to wear and tear.

Properties Metric Imperial
Density 7.85 g/cm3 0.284 lb/in³

AMS 6322 Mechanical Properties

AMS 6322 has a tensile strength of 880 MPa and a yield strength of 635 MPa. It also has a high fatigue limit, which means it can withstand high cyclic loading without breaking. The alloy’s toughness and flexibility make it an excellent choice in high-stress applications.

Properties Metric Imperial
Tensile strength 695 MPa 101000 psi
Yield strength 415 MPa 60200 psi
Elastic modulus 190-210 GPa 27557-30458 ksi
Bulk modulus (typical for steel) 140 GPa 20300 ksi
Shear modulus (typical for steel) 80 GPa 11600 ksi
Poisson’s ratio 0.27-0.30 0.27-0.30
Elongation at break (50mm) 22.20% 22.20%
Izod Impact 41 J 30.2
Hardness, Brinell 201 201
Hardness, Knoop (converted from Brinell hardness) 223 223
Hardness, Rockwell B (converted from Brinell hardness) 93 93
Hardness, Rockwell B (converted from Brinell hardness, value below normal HRC range, for comparison only) 13 13
Hardness, Vickers (converted from Brinell hardness) 211 211
Machinability (hot rolled and cold drawn, based on 100 machinability for AISI 1212 steel) 65 65

AMS 6322 Equivalents

DIN 1.6546 UNI 40 NiCrMo 2 KB B.S. Type 7 AMS 6322 AMS 6322F AMS 6323
AMS 6323D AMS 6325 AMS 6325D AMS 6327D AMS 6358 AMS 6358B
ASTM A322 ASTM A331 ASTM A505 ASTM A519 SAE J770 SAE J412
AMS 6327 MIL SPEC MIL-S-6049 AMS 7496 ASTM A29 ASTM A752 MIL S-6049
SAE J1397 ASTM A320 (L7C, L73) SAE J404

AMS 6322 Uses

AMS 6322 is widely used in aerospace, specifically for manufacturing landing gear components, gears, and shafts. In the automotive industry, the alloy is used to manufacture drive shafts and axles. AMS 6322 is also popular in the construction and engineering industries, where it is used to manufacture high-mechanical strength parts.

AMS 6322 Hardness

AMS 6322 has a Rockwell hardness of 42 HRc, making it suitable for parts that require excellent hardness and wear resistance. Its hardness also contributes to its excellent physical and mechanical properties.

AMS 6322 Heat treatment

AMS 6322 can be heat-treated to enhance its mechanical properties further. Typically, the alloy is heated to 870-920°C in a furnace and then quenched in oil or water. Heat treatment improves the alloy’s hardness, toughness, and strength.


AMS 6322 material is an excellent choice of alloy for parts that require high mechanical strength, excellent machinability, and weldability. Whether you need it for aerospace, automotive, construction, or engineering applications, the alloy’s excellent physical and mechanical properties make it a versatile and reliable option. Hopefully, this blog post has shed some light on what AMS 6322 is, its properties, and its uses, allowing you to make informed decisions when selecting a metal for your projects.

Related Post