ThePipingMart Blog Grades AMS 6370 Alloy Steel – Composition, Properties, and Uses

AMS 6370 Alloy Steel – Composition, Properties, and Uses

AMS 6370

SAE – AMS 6370 is a steel alloy widely used in various industries due to its outstanding mechanical and physical properties. If you’re working in engineering, manufacturing, or construction, you might have heard of this specific type of steel. However, for those new to this material, it’s worth taking the time to understand its composition, properties, uses, and heat treatment.

What is AMS 6370?

AMS 6370 (also known as SAE – AISI 4130 Alloy Steel) is not an average metal; it’s a high-strength, low-alloy steel that can handle extreme temperatures and pressure. AMS6370 is often used for structural parts and landing gear components in the aerospace industry. This metal provides the strength and durability needed for critical applications, making it a go-to material for engineers in the field. With its unique properties, SAE – AMS 6370 metal is a crucial component for ensuring the safety and reliability of aircraft.

What Form is AMS 6370 Available at Piping Mart?

  • Alloy Steel AISI 4130 Bars

AMS 6370 Composition

AMS 6370 steel bars is a medium carbon steel generally composed of 0.32% to 0.38% carbon, 0.70% to 1.00% manganese, 0.035% maximum phosphorus, and 0.040% maximum sulfur. It also contains 0.15% to 0.35% silicon, 0.4% to 0.6% chromium, and 0.4% to 0.6% molybdenum. With these elements combined, AMS 6370 material provides an excellent combination of hardness, strength, and toughness.

C Si Mn P S Cr Mo Fe
Min 0.28 0.15 0.40 0.80 0.15 0.00
Max 0.33 0.35 0.60 0.035 0.040 1.10 0.25 0.00

AMS 6370 Physical Properties

The physical properties of AMS 6370 bars include a density of 7.85 g/cm³ or 0.283 lb/in3 and a melting point of 1425°C or 2597°F. It also has good thermal conductivity, making it an ideal material for heat exchangers and other applications requiring efficient heat transfer.

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

AMS 6370 Mechanical Properties

AMS 6370 sheet demonstrates exceptional mechanical properties, such as high tensile strength, good ductility, and excellent wear resistance. Its tensile strength ranges from 885 MPa to 965 MPa, while its yield strength ranges from 747 MPa to 880 MPa. Moreover, AMS 6370 has a high hardness, around 247 to 302 Brinell hardness.

Properties Metric
Tensile strength, ultimate 560 MPa
Tensile strength, yield 460 MPa
Modulus of elasticity 190-210 GPa
Bulk modulus (Typical for steel) 140 GPa
Shear modulus (Typical for steel) 80 GPa
Poissons ratio 0.27-0.30
Elongation at break (in 50 mm) 21.50%
Reduction of area 59.6
Hardness, Brinell 217
Hardness, Knoop (Converted from Brinell hardness) 240
Hardness, Rockwell B (Converted from Brinell hardness) 95
Hardness, Rockwell C (Converted from Brinell hardness, value below normal HRC range, for comparison purposes only.) 17
Hardness, Vickers (Converted from Brinell hardness) 228
Machinability (Annealed and cold drawn. Based on 100% machinability for AISI 1212 steel.) 70

AMS 6370 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 6370 Specifications

Country USA BS BS Japan
Standard ASTM A29 EN 10250/EN10083 BS 970 JIS G4105
Grades 4130 25CrMo4/1.7218 708A25/708M25 SCM430

AMS 6370 Uses

One of the most common applications of AMS 6370 steel material is manufacturing gears, shafts, and other parts that require high strength and durability. It is also used in constructing pressure vessels, heat exchangers, and pipelines, with exceptional mechanical properties making it an ideal material for harsh environments. Furthermore, AMS 6370 can be employed in the aerospace, automotive, and military industries, where its excellent toughness and wear resistance make it a top choice.

AMS 6370 Hardness

AMS 6370 wire has a high hardness that ranges from 247 to 302 Brinell hardness. Its hardness is attributed to carbon, manganese, chromium, and molybdenum. This makes it ideal for applications where the steel will be subjected to high stress, wear, or impact.

AMS 6370 Heat treatment

Heat treatment is essential to obtain the desired mechanical properties for AMS 6370. The typical heat treatment process involves normalization, quenching, and tempering. It is usually quenched in oil or water and then tempered to improve flexibility and toughness.


In conclusion, understanding the properties and uses of AMS 6370 material is essential for professionals who work in various industries. Different industries find help for this type of steel due to its superior mechanical and physical properties. Its excellent strength, toughness, and wear resistance make it an ideal material for harsh environments. The right heat treatment must be done to obtain the desired mechanical properties. With proper utilization of AMS 6370steel, durable, efficient, and long-lasting products can be delivered.

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