Incoloy 825 is a nickel / iron / chromium alloy engineered with added titanium, copper and molybdenum for superior corrosion resistance in demanding engineering environments. The Incoloy name is a trademark registered by the Special Metals Corporation in the USA.


The main constituents of Incoloy 825 are as follows, given as percentages:

  • Nickel: 42%
  • Iron: 28.5%
  • Chromium: 21.5%
  • Molybdenum: 3%
  • Copper: 2.25%
  • Plus trace quantities of manganese, titanium, silicon, aluminium, sulphur and carbon

Common Industry Applications

Incoloy 825 has an impressive range of acid resistances. It also has a great temperature range, maintaining strength at extremely low temperatures, to heats as high as 400°C. It is therefore used in a range of extreme environments, including nuclear reactors and acid processing plants.

  • Nuclear industry
  • Oil and gas – especially high pressure applications
  • Acid manufacturing and processing


  • Excellent resistance to seawater
  • Excellent resistance to organic acids, sulfuric acid and nitric acid
  • Good resistance to alkalines, salts, hydrochloric acid, hydrofluoric acid and phosphoric acid
  • Reasonable resistance to aqueous chlorine
  • Extremely versatile thermal range with no loss of performance
  • Good crevice corrosion and pitting resistance


  • Cost: Incoloy 825 is more expensive than some other nickel alloys


At Hydraulics & Gas, we are happy to supply tube fittings and tubing made from high-quality Incoloy 825. Tubing is available in standard sizes of up to 25mm, with bespoke components available on request. We can supply a full range of fittings, including bulkhead couplings, adapters and compression fittings – in single and double ferrule. Get in touch for further details.

Alternative Trade Names: Alloy 825, UNS N08825