Inconel 625 is a high strength nickel-chromium alloy designed to resist corrosion and oxidation.  Inconel 625 operates at high temperatures in air and water. The alloy was developed in the 1960s for use as a lining material for steam pipes. Inconel 625 is a trademark currently owned by the Special Metals Corporation.


Inconel 625 is composed of the following metals, by percentage:

  • Nickel: 58%
  • Chromium: 21.5%
  • Molybdenum: 9%
  • Iron: 5%
  • Niobium & Tantalum: 3.65%
  • Plus trace elements of manganese, titanium, silicon, sulphur, carbon, cobalt, silver and phosphorus

Common Industry Applications

The composition of Inconel 625 makes it ideal as a welding material, while its niobium content makes it resistant to extremely harsh environments. The alloy is therefore ideally suited to high performance environments in a number of extreme applications.

  • Aerospace manufacturing
  • Defence applications
  • Underwater pipelines
  • Chemical processing
  • Ship and submarine motors and propellers
  • Oceanographic instruments


  • Excellent sea water resistance
  • Excellent chloride resistance
  • Versatile, strong and easy to weld


No notable disadvantages.


We keep in stock a range of compression fittings for high and low pressure systems, plus Inconel 625 tubing in a variety of lengths.

Alternative Trade Names: Alloy 625, Nickel Alloy 625 and UNS N06625