6MO Stainless Steel is a stainless steel alloy that takes its name from the use of molybdenum in its composition. To qualify as alloy 6MO, the steel must have at least 6% of molybdenum (MO) by volume.


6MO Stainless Steel alloy incorporates the following metals. It differs from 316 Stainless Steel in its molybdenum, chromium and nitrogen content.

  • Iron: 44.75%
  • Nickel: 25%
  • Chromium: 20%
  • Molybdenum: 6.5%
  • Manganese: 2%
  • Trace quantities of copper, silicon, sulphur, carbon, phosphorus and nitrogen

Common Industry Applications

6MO is commonly used for welded and seamless tubing, compression fittings and custom fabrications. Its good corrosion resistant properties mean it can be used in a wide range of liquid processing and pollution control applications:

  • Marine industry
  • Desalination plants
  • Air and water purification plants
  • Food & drink processing
  • Oil and gas industry


  • Good resistance to pitting and crevice corrosion
  • Excellent tolerance of seawater
  • More cost-effective than other nickel alloys
  • High melting point makes 6MO an excellent choice for high temperature applications
  • Moderate resistance to chloride
  • Technically versatile
  • Raw materials are quickly and cheaply available


No significant disadvantages compared with other metals within the same price range.


At Hydraulic & Gas we supply a wide range of 6MO components, with custom fabrications available on request:

  • Tubes - Tubing available in any length, with a minimum order of 1m Fittings – We hold a wide range of tube fittings in stock, with material available to quickly process bespoke requests. Fittings include compression fittings, adapters, bulkhead couplings etc. All main thread types are available.

Alternative Trade Names: 6Moly, 6MO, 254 SMO, 6% Moly Alloy, Alloy 254