Which Metals Are Marine Grade?

Last Updated on July 1, 2020 by Marsh Fasteners

Underwater and wet environments are highly corrosive to metals. To prevent the material from failing in these conditions it may be necessary to rely on metals to which alloying elements have been added in order to defend against the corrosive effects. Below we look at 3 of the popular marine grade metals:




Marine grade aluminum is generally restricted to 5XXX and 6XXX grades. It has great corrosion resistance along with precipitation hardening. Higher levels of chromium and manganese are present, which increase the aluminum’s corrosive resistance. Common marine-grade aluminum alloys are:



This an excellent marine grade for when formability is required.


  • Grade 5083 & 5086


If strength is more of a concern, then this grade is a good alternative.


  • Grade 6061-T6


This is an all-around popular grade of aluminum that is also commonly used in marine applications.


  • Applications

Shipbuilding, oil rig construction, shipyard infrastructure, docks, booms, and rigs.



  • Stainless Steel


All grades of stainless steel have some degree of corrosion resistance; however, there are several grades of stainless steel that are far more suitable for use in marine environments than others:


  • Grade 316


This grade tends to have more nickel and molybdenum in the alloy than other austenitic stainless steels, which helps it to resist pitting and the other corrosive effects of salt water.


  • Grade 304


This grade has less molybdenum, which makes it a less desirable choice in chlorine-rich environments.



  • Applications


Barriers, fence rails/banisters, marine fittings and fasteners, and marine structures.



  • Copper


Copper is not only used in many marine-based applications, but also in the brewing and distilling industries, plumbing, and appliance design and repair. There are several copper-nickel alloys suitable for marine applications, which include:

  • C70600

This alloy contains nickel and manganese to help resist corrosion.


  • C71500


This alloy has a similar makeup to alloy C70600, but contains even more nickel in its chemical composition, and is also able to withstand marine conditions.



  • Applications


Marine fittings, fasteners, valves, pumps, water lines, desalination equipment, plumbing tubes, heat exchanger tubes, and distilling and brewing systems.


Marine Grade Metals from Marsh Fasteners


Marsh Fasteners is the leading marine grade metal provider in Jupiter, Florida. With the vast number of new marine grade metals available, you need our expertise more than ever. To discuss your specific requirements contact the metal experts at Marsh Fasteners today.

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