ThePipingMart Blog Grades AMS 4130 Alloy Steel – Composition, Properties, and Uses

AMS 4130 Alloy Steel – Composition, Properties, and Uses

AMS 4130

Regarding steel grades, AMS 4130 is popular for aerospace, oil and gas, and automotive applications. This alloy steel is designed to have high durability, strength, and toughness, making it ideal for applications requiring wear resistance, corrosion, and fatigue. This blog post will closely examine what AMS 4130 is, its composition, physical and mechanical properties, uses, and heat treatment processes.

What is AMS 4130?

AMS 4130 (also known as Bar) is a type of steel alloy that has gained popularity recently due to its exceptional strength and durability. It is often used in aerospace, oil and gas, and automotive manufacturing industries. Its ability to withstand extreme temperatures and high-stress situations sets AMS 4130 apart from other steel alloys, making it a top choice for critical applications. In addition to its superior physical properties, AMS 4130 is also known for its excellent weldability and machinability, making it a versatile material for various projects. Whether you’re building a rocket engine or a race car, AMS 4130 is a reliable choice that won’t disappoint you.

What Form Is AMS 4130 Available at Piping Mart?

  • Alloy Steel Aisi 4130 Bars

AMS 4130 Composition

AMS 4130 is an alloy steel that belongs to the AISI 41xx series. This steel grade comprises several elements, including carbon, manganese, silicon, chromium, molybdenum, and phosphorus. The carbon content in AMS 4130 is between 0.28% to 0.33%, making it a low-carbon alloy steel. Chromium and molybdenum are added to improve the steel’s hardenability, while silicon and manganese help enhance its strength and toughness.

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 4130 Physical Properties

The physical properties of AMS 4130 include a density of approximately 7.85 g/cm3, a melting point of 1432°C, and a thermal conductivity of 45.9 W/m-K. It also has a coefficient of thermal expansion of 11.7 µm/m-K, indicating that it is more resistant to thermal expansion than other steel grades.

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

AMS 4130 Mechanical Properties

The mechanical properties of AMS 4130 vary depending on the heat treatment process used. In its annealed condition, it has a tensile strength of 415 MPa and a yield strength of 205 MPa. However, after being heat-treated, its tensile strength can increase to up to 850 MPa, making it a high-strength steel grade. Its elongation at break is around 20%.

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 4130 Thermal Properties

Properties Metric Imperial
Thermal conductivity (100°C) 42.7 W/mK 296 BTU in/hr.ft2. °F

AMS 4130 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 4130 Uses

AMS 4130 is a versatile steel grade used in various industries. In the aerospace industry, it is used to make aircraft parts such as landing gears, engine components, and structural frames. In the oil and gas industry, it is used for making drilling equipment, pump shafts, and other components exposed to corrosive environments. In the automotive industry, it is used to make high-performance parts like suspension components, drive shafts, and gears.

AMS 4130 Hardness

The hardness of AMS 4130 can vary depending on the heat treatment process. In its annealed condition, it has a Rockwell hardness of B82. However, after being heat-treated and quenched, it can reach up to Rockwell C50.

AMS 4130 Heat Treatment

Heat treatment is a crucial process for improving the mechanical properties of AMS 4130. The most common heat treatment process used is quenching and tempering. This involves heating the steel to a specific temperature, rapidly cooling it in a liquid like oil or water, and then tempering it at a lower temperature to reduce its brittleness and increase its toughness. Other heat treatment processes include normalizing, annealing, and stress relieving.


In conclusion, AMS 4130 is a high-strength alloy steel grade with excellent physical and mechanical properties. Its composition and heat treatment capabilities make it suitable for various industries requiring its strength, toughness and wear resistance. Understanding the properties and uses of AMS 4130 is essential for selecting the right steel grade for your application and ensuring its longevity and durability.

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