• BS 3076 NA21
  • 2.4856
  • ASTM B564
  • SAE AMS 5666
  • ASTM B466
  • UNS N06625
  • Nace MR01-75 / ISO 15156
  • ASME SB466
View Data Tables For This Product

Alloy 625 (AMS5666) (UNS N06625)

Alloy 625, often referred to as Inconel 625 (where Inconel is a trademark of Special Metals Corp) is a nickel-chromium-molybdenum-niobium alloy (NiCr22Mo9Nb).

Continue reading this page to find out more about Alloy 625 from Langley Alloys.


What Is Alloy 625 Used For?

Alloy 625 is perfectly suited to the most demanding applications, from sub-zero to extremely high-temperature environments. It achieves these levels of high strength as a result of the solid solution effects of molybdenum and niobium (also known as Colombium) from room temperatures up to 800°C. Alloy 625 is usually supplied in the hot worked and annealed condition.

Alloy 625 is particularly useful in situations where oxidation resistance and avoidance of pitting are required. In the annealed condition, this Inconel Alloy is fully austenitic and suitable for machining. It provides excellent corrosion resistance in a wide variety of severely corrosive environments due to its high alloy content. With nearly 60% nickel composition it is virtually immune from stress corrosion cracking.

Alloy 625 is non-magnetic and able to operate over a wide temperature range, from cryogenic temperatures up to 980degC. This supports applications in jet engines, heat exchangers, furnace hardware and chemical plant equipment.

Alloy 625 From Langley Alloys

Langley Alloys can supply Alloy 625 in a variety of different industry specifications. It is primarily offered as ASTM B446 for applications within the chemical process and Oil and Gas industries.

Langley Alloys carries an extensive stock of Alloy 625 from 0.5″ (12.7mm) to 10″ (254mm) diameter solid bars that meet ASTM B446 Grade 1 and Grade 2 plus SAE AMS 5666 requirements.

The most common specification is Alloy 625 Grade 1, although Langley Alloys are also able to offer Alloy 625 Grade 2 when required. For aerospace-related applications, we can also provide Alloy 625 in compliance with SAE AMS 5666.

stainless steels


  • BS 3076 NA21
  • 2.4856
  • ASTM B564
  • SAE AMS 5666
  • ASTM B466
  • UNS N06625
  • Nace MR01-75 / ISO 15156
  • ASME SB466
View Data Tables For This Product

Data Tables

Chemical Composition:


Mechanical Properties:

Bars up to and including 4” diameter or sectionBars above 4” diameter or section
0.2% Proof Stress415 N/mm260ksi345 N/mm250ksi
Tensile Strength830 N/mm2120ksi760 N/mm2110ksi
Elongation, 5.65√S0 and 4D30%25%
Reduction of Area35%35%
Hardness (Brinell)


  1. Tensile testing shall be carried out in accordance with ASTM A370 or EN10002-1
  2. Minimum properties quoted (tested at room temperature in a longitudinal direction)
  3. Testing performed on each melt of material per heat treatment batch

Physical Properties:

Density (Kg.m-1)84.4
Magnetic Permeability (20°C)<1.001
Curie Temperature (°C)-196
Young’s Modulus (N/mm2)207.5
Specific Heat, 20°C (J/(g.K))410
Specific Electrical Resistance, 20°C (Ω-m)0.0129
Thermal conductivity, 20°C (W/(m.K))9.9
Mean coefficient of thermal expansion, 20-100°C (/K)12.8 x 10-6

Product Features

Key Features:

  • Good strength/ductility properties from sub-zero temperatures to over 980°C
  • Excellent corrosion and fatigue resistance in a wide variety of corrosive environments including seawater and industrial acids
  • Non-magnetic and spark resistant
  • Resistant to high temperature oxidation and carburisation
  • Excellent resistance to stress corrosion cracking



  • Wellhead components
  • Sheathing, Fasteners, Clamps
  • Downhole equipment for corrosive/sour service
  • Propellers and Shafts
  • Propulsion Motors
  • Fasteners
  • Reactor core & control rod components
  • Chemical process equipment


Contact Our Team

If you would like to know more about Alloy 625, feel free to call our helpful team today for more information or to request a quote. You can also visit our contact page where you can request a quote and discover further contact details for both locations.

Our team has gained industry experience and knowledge over the years, and are more than happy to help with any questions you may have. Get in touch today.

Datasheet NA Alloy 625
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