ThePipingMart Blog Grades AMS 6488 Tool Steel – Composition, Properties, and Uses 

AMS 6488 Tool Steel – Composition, Properties, and Uses 

AMS 6488

When it comes to high-performance alloys, AMS6488 holds a significant position. Also known as Alloy 718, this alloy is used extensively in the aerospace industry to produce critical components, such as turbine discs, casings, and blades. AMS 6488 is a nickel-based superalloy with remarkable strength, durability, and high-temperature corrosion resistance. This blog post will closely examine this famous alloy and uncover important details about its composition, physical and mechanical properties, heat treatment, hardness, and uses.

What is AMS 6488?

AMS 6488 (also known as H-11 Tool Steel) alloy is known for its exceptional toughness and ability to withstand extreme temperatures. It’s made up of a combination of Nickel, Chromium, and molybdenum, giving it fantastic corrosion resistance properties. AMS6488 is frequently used in applications such as aircraft landing gear, hydraulic systems, and missile components. If you’re looking for a material that can handle the toughest conditions and the greatest stresses, AMS6488 metal is certainly worth considering.

AMS 6488 Composition

AMS6488 is a nickel-based superalloy composed of several elements, including Nickel, Chromium, molybdenum, iron, and niobium. The primary ingredient in AMS 6488 is Nickel, which forms the alloy’s bulk, providing excellent corrosion resistance, elasticity, and ductility. On the other hand, Chromium enhances the oxidation resistance and overall strength of AMS 6488. Molybdenum and niobium increase the alloy’s strength, hardness, and high-temperature performance.

Element Content (%)
Carbon, C 0.33-0.43
Manganese, Mn 0.20-0.50
Silicon, Si 0.80-1.20
Chromium, Cr 4.75-5.50
Nickel, Ni 0.3
Molybdenum, Mo 1.10-1.60
Vanadium, V 0.30-0.60
Copper, Cu 0.25
Phosphorous, P 0.03
Sulfur, S 0.03
Iron, Fe Balance

AMS 6488 Physical Properties

AMS 6488 has outstanding physical properties, which make it a popular choice for high-temperature applications. The alloy has a density of 8.19g/cm3, lower than many other nickel-based superalloys. AMS 6488 exhibits excellent thermal conductivity at both low and high temperatures. The alloy also has remarkable thermal stability, which allows it to maintain its form and retain its mechanical properties under high-temperature stress.

Properties Metric Imperial
Density 7.81 g/cm3 0.282 lb/in3
Melting point 1427°C 2600°F

AMS 6488 Mechanical Properties

AMS 6488 is known for its high strength and durability. The alloy has a tensile strength of 145 ksi and a yield strength of 90 ksi at room temperature. However, its mechanical strength increases significantly at high temperatures, making it an ideal choice for high-temperature applications. AMS 6488 has an impressive fatigue life and excellent corrosion resistance in various environments.

Properties Metric Imperial
Hardness, Rockwell C (air cooled from 982°C, 45 mins) 52.5 52.5
Hardness, Rockwell C (air cooled from 1010°C, 45 mins) 56 56
Hardness, Rockwell C (air cooled from 1038°C, 45 mins) 57 57
Modulus of elasticity 207 GPa 30000 ksi
Modulus of elasticity (@538°C/1000°F) 159 GPa 23000 ksi
Modulus of elasticity (@204°C/400°F) 190 GPa 27500 ksi
Charpy impact (V-notch; air cooled from 1010°C;535°C temper temperature) 13.6 J 10.0 ft-lb
Charpy impact (V-notch; air cooled from 1010°C;650°C temper temperature) 27.1 J 20.0 ft-lb
Charpy impact (V-notch; air cooled from 1010°C;370°C temper temperature) 33.9 J 25.0 ft-lb
Machinability (1% carbon steel) 75.0 – 80.0% 75.0 – 80.0%
Poisson’s ratio 0.27-0.30 0.27-0.30

AMS 6488 Equivalents

AFNOR Z 38 CDV 5 AMS 6485 SAE J438
DIN 1.2343 AMS 6487 SAE J467
UNI KU AMS 6488 UNS T20811
B.S. BH 11 FED QQ-T-570 ASTM A579
AMS 6437 SAE J437 MIL S-47262

AMS 6488 Uses

Due to its remarkable physical and mechanical properties, AMS 6488 is widely used in the aerospace industry to produce critical components, such as turbine discs, casings, and blades. The alloy also makes structural components in the oil and gas industry. AMS 6488 is popular for manufacturing components requiring high strength, durability, and thermal and mechanical stress resistance.

AMS 6488 Hardness

AMS 6488 exhibits remarkable hardness, making it suitable for high-stress applications. The alloy’s hardness depends on various factors, including the heat treatment it has undergone. In the solution-annealed condition, AMS 6488 has a Brinell hardness of around 270 HB before precipitation hardening. However, its hardness increases significantly after heat treatment, reaching up to 600 HB.

AMS 6488 Heat treatment

AMS 6488 is heat-treated to improve its mechanical properties and enhance its overall strength. Heat treatment involves three stages: solution annealing, quenching, and precipitation hardening. The solution annealing stage involves heating the alloy to a temperature range of 1650-1750°F, which dissolves the precipitates in the material. The quenching stage involves rapidly cooling the material, which results in the formation of a fine-grained microstructure. Precipitation hardening is the final stage, which involves heating the material to a temperature range of 1300-1350°F, followed by cooling in water.


In conclusion, AMS 6488 material is a remarkable nickel-based superalloy used extensively in the aerospace industry due to its exceptional strength, durability, and corrosion resistance. Its composition, physical and mechanical properties, hardness, heat treatment, and uses make it a prime choice for high-performance applications. Whether you want to manufacture turbine discs, casings, or blades, AMS 6488 is a go-to alloy. Its remarkable hardness, excellent thermal stability, and ability to maintain its mechanical properties under high-stress conditions make it the preferred choice for high-temperature applications.

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