Aerospace Fittings

Aerospace Fittings - AN,AS and MS nuts and sleeves for tube assembly

Buy Aerospace Fittings From A Trusted Source!

Online Metals Depot is a leading supplier of Aerospace fittings and adapters for the aviation and aerospace industries. Our Aerospace fittings are sourced from certified aerospace fitting manufactures so you can install right on the aircraft without worry. We stock a variety of fittings in various materials and sizes. All of our aerospace fittings come with a minimum mfg. C of C so you can rest assured you are getting a certified part ready for install directly on the aircraft.


What does AN, MS and AS stand for? 

  • AN - Stands for Army / Navy. Used in the early 1940's to standardize military items for WWII. Some AN part#'s are still used today.
  • MS -  Military standard that for the most part replaced the AN hardware. The MS series was cancelled in 1994 by the secretary of defense. However this caused problems in the aerospace industry because many commercial companies used MS for all or their products. This caused a rush to come up with a new standard to replace the MS standards. There are still some MS part numbers manufactured and used today to support the older aircraft that still requires the MS part#
  • AS - With the demise of the MS standards a new spec had to be created and that was the AS standards which SAE now governs. Some MS and AN standards were replaced by AS standards and some were changed all together. For example the AN818 nut is now AS5175 and the AN819, MS20819 sleeves are now AS5176.



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