ThePipingMart Blog Grades AMS 6361 Alloy Steel – Composition, Properties, and Uses

AMS 6361 Alloy Steel – Composition, Properties, and Uses

AMS 6361

The AMS6361 is a steel alloy that finds an extensive range of applications in various industries. It features excellent mechanical and physical properties, making it suitable for high-temperature and high-pressure environments and in aerospace and structural industries. This blog post will discuss the composition, physical and mechanical properties, uses, hardness, and heat treatment of AMS 6361 steel alloy.

What is AMS 6361?

AMS 6361 (also known as AISI 4130 Alloy Steel) is a specification created by the Aerospace Materials Division of the Society of Automotive Engineers (SAE) for seamless tubing made from steel with high-temperature properties. It is commonly used in aerospace applications where high strength and corrosion resistance are necessary. The specification outlines the chemical composition, heat treatment, and mechanical properties required for the steel tubing to meet the stringent demands of the aerospace industry. With AMS6361, manufacturers can ensure that their products are reliable and capable of withstand extreme environments’ rigours. Whether for aircraft engines or rocket propulsion systems, AMS6361 has become the standard for high-temperature steel tubing.

What Form is AMS 6361 Available at Piping Mart?

  • Alloy Steel AISI 4130 Bars

AMS 6361 Composition

The AMS6361 alloy has a chemical composition of 0.22-0.28% Carbon, 0.75-1.15% Manganese, and 0.70-0.90% Chromium. The alloy also contains traces of Nickel, Silicon, and Molybdenum. Combining these elements enhances the alloy’s strength and toughness, making it ideal for manufacturing critical components.

Element Content (%)
Iron, Fe 97.03 – 98.22
Chromium, Cr 0.80 – 1.10
Manganese, Mn 0.40 – 0.60
Carbon, C 0.280 – 0.330
Silicon, Si 0.15 – 0.30
Molybdenum, Mo 0.15 – 0.25
Sulfur, S 0.040
Phosphorous, P 0.035

AMS 6361 Physical Properties

The AMS 6361 alloy has a density of 7.85 g/cm3, making it a high-density alloy. The thermal conductivity of the AMS 6361 alloy is 46.6W/mK, which is excellent for high-temperature applications. The alloy also exhibits a coefficient of thermal expansion of 11.7 µm/m°C, which enables it to withstand extreme temperatures by reducing thermal stress.

Properties Metric Imperial
Density 7.85 g/cm3 0.284 lb/in³
Melting point 1432°C 2610°F

AMS 6361 Mechanical Properties

The mechanical properties of the AMS 6361 alloy make it suitable for high-stress environments. It features a minimum yield strength of 690 MPa, a minimum tensile strength of 790 MPa, and an elongation of up to 13%. The alloy’s remarkable toughness and flexibility enable it to withstand extreme pressure and harsh environments.

Properties Metric Imperial
Tensile strength, ultimate 560 MPa 81200 psi
Tensile strength, yield 460 MPa 66700 psi
Modulus of elasticity 190-210 GPa 27557-30458 ksi
Bulk modulus (Typical for steel) 140 GPa 20300 ksi
Shear modulus (Typical for steel) 80 GPa 11600 ksi
Poissons ratio 0.27-0.30 0.27-0.30
Elongation at break (in 50 mm) 21.50% 21.50%
Reduction of area 59.6 59.60%
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.) 70 70

AMS 6361 Equivalents

AMS 6348 AMS 6371 ASTM A331 ASTM A829 DIN 1.7218
AMS 6350 AMS 6373 ASTM A506 MIL S-18729 UNI 25 CrMo 4
AMS 6351 AMS 6374 ASTM A507 MIL S-6758 JIS SCCrM 1
AMS 6360 AMS 6528 ASTM A513 SAE J1397 JIS SCM 2
AMS 6361 AMS 7496 ASTM A519 SAE J404 SS 2225
AMS 6362 ASTM A29 ASTM A646 SAE J412 B.S. CDS 110
AMS 6370 ASTM A322 ASTM A752 AFNOR 25 CD 4 (S) SAE J770

AMS 6361 Uses

Due to its excellent mechanical and physical properties, the AMS 6361 alloy is widely used in manufacturing aerospace components, high-pressure pipes, and structural components. The alloy is also ideal for manufacturing power generation turbines, pressure vessels, and hydraulic cylinders. The alloy’s toughness and strength properties have also made it an essential material for manufacturing automotive and industrial parts.

AMS 6361 Hardness

The AMS 6361 alloy features a Rockwell hardness of B84, which is considered hard. The alloy’s hardness can withstand extreme pressure and high temperatures without deforming. The alloy’s hardness also makes it an excellent material for manufacturing cutting tools and high-quality blades that require high durability.

AMS 6361 Heat treatment

The AMS 6361 alloy is heat-treatable and requires a specific heat-treatment process to achieve desired mechanical properties. The alloy must be quenched in water at 920°C and then tempered at 550°C. This process enhances the material’s strength, hardness, and toughness, making it ideal for high-stress environments.


The AMS 6361 steel alloy is a reliable material with excellent physical and mechanical properties, making it suitable for various aerospace, structural, and automotive applications. Its hardness, strength, and toughness make it ideal for manufacturing components that require high durability and resistance to extreme pressures and temperatures. The heat-treatment process enhances its properties, making the alloy withstand harsh environments. With its impressive properties, it is evident why the AMS 6361 steel alloy is highly sought after in the manufacturing industry.

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