Monel 400 is a high-performance nickel alloy with excellent corrosion resistant properties. Monel alloys were first developed in 1901 by Robert Stanley of the International Nickel Company. The name comes from Ambrose Monell, the director of the company when the alloy was patented in 1906. Monel is now a trademark owned by the US Special Metals Corporation. Monel 400 can readily be welded, machined and fabricated, leading to a variety of applications in a range of industries.


Monel 400 includes the following elements, by average composition. Some Monel alloys include up to 67% nickel.

  • Nickel: 63.7%
  • Copper: 31%
  • Iron: 2.5%
  • Manganese: 2%
  • Plus trace quantities of silicon, sulphur and carbon


  • Stress and fracture resistance in freshwater
  • Good thermal conductivity
  • High tactile strength
  • Excellent sea water resistance
  • Resistance to fast flowing water
  • Excellent resistance to alkaline, salts and hydrofluoric acid
  • Good resistance to hydrochloric acid and chloride


  • Cost: Monel 400 costs 5 to 10 times as much as copper or nickel, and 3 times as much as carbon steel. It is only therefore used when the required performance characteristics cannot be gained from a cheaper alloy
  • Monel 400 is vulnerable to oxidising salts, which will reduce its resistance to hydrochloric acid

Common Industrial Applications

The strengths of Monel 400 make it a good choice for high performance applications in a variety of settings, including:

  • Heat exchangers
  • Pumps and valves
  • Marine engineering
  • Aerospace manufacturing
  • Oil refining


We hold stock of tube fittings and tube lengths in Monel 400, plus a quantity of raw material for custom orders. Fittings include elbows, tees, couplings etc. A variety of sizes and thread types are available. Due to the machining requirements, Monel 400 components come with a longer lead time than standard parts in 316 stainless steel.

Alternative Trade Names: Alloy 400, UNS N04400, Monel Alloy