ThePipingMart Blog Grades AMS 5666 Inconel Alloy – Composition, Properties and Uses

AMS 5666 Inconel Alloy – Composition, Properties and Uses

AMS 5666 Inconel Alloy

In today’s rapidly advancing world, technology is increasingly dominant in every aspect of our lives. As such, there is a growing demand for solid and durable materials that can withstand high-stress applications. AMS5666 is an alloy that fits this description perfectly. AMS 5666 is commonly used in high-temperature applications, such as gas turbine components, due to its exceptional strength and resistance to corrosion. This article will explore this superalloy’s composition, physical and mechanical properties, and various applications.

What is AMS 5666?

AMS 5666 (also known as Inconel 625) metal is a high-performance alloy used in various industries. It is made from a combination of nickel, chromium, molybdenum, and iron, which gives it exceptional strength and versatility. This metal can withstand high temperatures and corrosive environments, making it a popular choice for applications in aerospace, chemical processing, and oil & gas. AMS5666 is known for its excellent oxidation resistance and ability to maintain its structural integrity in extreme conditions. With its remarkable properties, it’s no wonder why this metal is in such high demand.

What Form is Available at AMS 5666 Piping Mart?

  • Nut
  • Bar
  • Bolt
  • Pipe
  • Screw
  • Tubing
  • Valves
  • Washers
  • Flanges
  • Fasteners
  • Electrodes
  • Stud Bolts
  • Sheet Plates
  • Pipe Fittings
  • Forged Fitting

AMS 5666 Composition

AMS 5666 is a nickel-based superalloy that contains chromium, molybdenum, and iron as its primary constituents. It also includes small amounts of carbon, titanium, and aluminium to enhance its mechanical properties. The nickel-chromium combination gives it excellent resistance to corrosion and oxidation at high temperatures, while molybdenum and iron contribute to its high strength and durability. The precise composition of AMS 5666 differs depending on the manufacturer and application.

NI 58.0 min
AL 0.40 max
FE 5.0 max
MN 0.50 max
C 0.10 max
SI 0.50 max
S 0.015 max
P 0.015 max
CR 20.0 – 23.0
NB + TA 3.15 – 4.15
MO 8.0 – 10.0
TI 0.40 max

AMS 5666 Physical Properties

AMS 5666 has a density of 8.2 g/cm³ and a melting point of 1390°C. It also has high thermal conductivity and a low coefficient of thermal expansion. Its excellent thermal stability makes it a top choice in high-temperature applications.

DENSITY 8.44 g/cm 3 / 0.305 lb/in 3
MELTING POINT 1290 -1350 (°C) / 2350 – 2460 (°F)
SPECIFIC HEAT @ 70°F 0.098 Btu/lb/°F
CURIE TEMPERATURE -190 (°C) / < -320 (°F)
YOUNG’S MODULUS (N/MM2) 205 x 10
ANNEALED 871 (°C) / 1600 (°F)
QUENCH Rapid Air

AMS 5666 Mechanical Properties

The outstanding mechanical properties of AMS 5666 make it ideal for high-stress applications. It has a tensile strength of up to 1000 MPa and can handle temperatures up to 982°C. It also maintains its mechanical strength even at high temperatures, making it an ideal material for use in high-stress environments. AMS 5666 can also withstand high-frequency vibrations, making it suitable for components in gas turbine engines.

PROPERTY 21°C 204 °C 316 °C 427 °C 538 °C 649 °C 760 °C 871 °C
Ultimate Tensile Strength /Mpa 992.9 923.9 910.1 910.1 896.3 820.5 537.8 275.8
0.2% Yield Strength /MPa 579.2 455.1 434.4 420.6 420.6 413.7 406.8 268.9
Elongation % 44 45 42.5 45 48 34 59 117
Coefficient of Thermal Expansion µm/m⁰C 13.1 13.3 13.7 14 14.8 15.3 15.8
Thermal Conductivity /kcal/(hr.m.°C) 8.5 10.7 12.2 13.5 15 16.4 17.9 19.6
Modulus of Elasticity/ MPa 2.07 1.93 1.93 1.86 1.79 1.65 1.59

AMS 5666 Equivalent

Inconel 625 2.4856 N06625 NCF 625 ХН75МБТЮ NA 21 NC22DNB4MNiCr22Mo9Nb NiCr23Fe

AMS 5666 Uses

The exceptional properties of AMS 5666 make it the preferred material for use in high-temperature applications. It is often used in gas turbine components, such as combustion rings and transition ducts, where it is exposed to high temperatures, corrosive environments, and mechanical stresses. AMS 5666 is also used in the aerospace industry for heat exchangers and afterburner components due to its exceptional strength and resistance to fatigue.

AMS 5666 Hardness and Heat Treatment

AMS 5666 can be subjected to various heat treatments to achieve the desired properties. It is typically heat-treated at around 1093°C to 1150°C to enhance its strength and mechanical properties. After heat treatment, AMS 5666 has a hardness level of 25 and 34 HRC, making it suitable for high-stress applications.


AMS 5666 material is a special nickel-based superalloy with properties ideal for high-temperature and high-stress applications. Its excellent thermal stability, mechanical properties, and resistance to corrosion and oxidation at high temperatures make it a top choice for gas turbine components and other high-stress applications. So, the applications are endless when it comes to this superalloy.

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