Different have been developed and are currently employed in the procurement of fasteners by the Armed Forces, national and international agencies and industrial companies around the world in their attempt for uniform quality by establishing baselines for fastener characteristics, manufacturing processes, terminology, and expectations.These Standards cover a variety of required information on fasteners like their physical characteristics, like their inch or metric dimensions/tolerances, their material composition and chemical properties, property test methods, procedural instructions for fastener uses, terminology including definitions, symbols, or other identifying factors of the fastener, and so on.

Fastener Standards have proliferated over the years to keep pace with new fastener types, their designs, and materials, industrial requirements or as part of changes in the standardisation policies in different countries. In many cases, Standards originally developed for the procurements of fasteners by the Armed Forces / Defence Ministries have been updated to include industrial needs and converted to industry standards.

U.S Aerospace / Military Fastener Standards are briefly presented below and include Army-Navy (AN), predecessor to "Military Standards " (MS)  and subsequent NAS (National Aerospace Standards) which followed. In addition, all fasteners are identified with a specification number and a series of letters and dashes identifying their size, type of material, etc. This system presents a relatively simple method of identifying and cataloging the thousands of hardware items, several of them coming both an AN number and an MS number that are used interchangeably to identify the exact same item. Cross reference tables have been created and are currently used. Such information are also included in respective product presentations at our Web Platform for Supplies for our offered product lines briefly discussed below.

Other Fastener Standards for Aerospace and Industrial (Commercial) applications are used like those from standardization bodies listed below and separately discussed without being by any means an exhaustive list.
ISO – International Organization for Standardization
EN (European Norm)
British Standards
DIN – Deutsches Institute for Normung (German National Standards Institute)
ASME – American Society of Mechanical Engineers
ANSI – American National Standards Institute
SAE International – Society of Automotive Engineers
ASTM International – American Society for Testing and Materials

It should be noted that fastenrs used in commercial/industrial applications are very similar to those used in aerospace/military projects.In many cases they  look and behave in the same way with key differences being the exacting measurements and tolerance required for aerospace/military uses.

Army-Navy Standards (AN)

Predecessor to Mil-Spec (MS), U.S Army & Navy (AN) Standards fasteners were for many years the industry standard for aircraft, indicating that these fasteners were made to military specifications to stand up to demanding appllications without faltering.

Military Specification  (Mil-Spec, MS)

U.S. Department of Defence Standards for military or defence equipment known as Military Specification, Mil-Spec, MS or MIL-STD. They  have been developed to help achieve standardization objectives by the U.S. Department of Defence but also used by other non-Defence government organizations, technical organizations, and the industry. In many cases, MS uses other standards to define their own. For example, an MS fastener may use an ASTM standard to regulate testing methods, and/or may use a SAE standard to establish material requirements.

National Aerospace Standards (NAS)

National Aerospace Standards (NAS), by the U.S Aerospace Industries Association (AIA), supersede those of Army & Navy (AN) and Military Specifications (MS). AIA, in coordination with the US Department of Defence, has converted a number of MIL-spec's to NAS. NAS are voluntary standards developed and maintained by committees and working groups of subject matter experts from AIA member companies. They are widely used for high-precision, high-strength applications in aerospace and defence. These standards have served as the foundation for the development of aircraft, spacecraft, watercraft, ground vehicles, machinery, and electronics.

NAS parts are most well-known for state-of-the-art, high-strength, precision fasteners, electrical connectors, splices and terminations, rod end bearings, and many other types of hardware and components. They are offered in Imperial (inch) or Metric (mm) systems. NAS prefix is used for parts in inch measurement system while NASM, NA or NAM prefixes are used for Metric parts, representing the metric conversion of many original imperial NAS / Military Specification (MS) parts. Up to now approximately 500 military standards have been updated and converted by the NAS group, although, despite the conversion, fasteners are often still procured on the basis of their original MS (Military Standard) or Army-Navy (AN) part numbers.

NAS fasteners include an extensive range of  screws and bolts, nuts, anchor nuts, rivets and many others structured in different series and offered in different sizes. Respective codes in their part numbers are used to denote their material, finish and other characteristics. They are listed separately in our Web Platform for Supplies.These fasteners are oulined below while additional information is provided through articles and other documentation available in our Repository.  

Machine screws (also termed as bolts) for structural and non-structural applications offered in different materials (such as steel and stainless steel alloys) and finishes. Indicative NAS series of machine screws/bolts include NAS  220, 229, 333,  514,  517, 560, 583, 584, 600, 623, 662, 860, 870, 1101, 1102, 1189, 1190, 1191, 1581, 1630, 1635, 1801, and 1802. 

Anchor nuts (also termed as nut plates) of both fixed and floating types in different configurations, in inch or metric systems . NAS 1791 (two-lug) and 1792 (one-lug) series of floating self-locking nut plates with replacement nut elements or NA-0027/ NA-0028 series of metric self-locking floating two-lug anchor nuts are examples of these fasteners. NAS 1473 series of floating self-locking two-lug capped nut plates and their NAS 1474 series counterparts with reduced rivet spacing, or NASM 21059 / 21060 floating self-locking, low height two-lug nut plates, superseding the respective anchor nuts of MS 21059 / MS 21060 series, also fall in this category.

Hexagon (Hex) nuts like the NAS 1423 / NAS 509 series drilled jam nuts, the NASM 316 series thin non-locking jam nuts replacing those of AN 316 series, the self locking machine nuts of NAS 1022 series, or the low height self-locking nuts of NASM 21083 series, superseding those of MS 21083 and AN 364 series, are included in the range of NAS Standard fasteners.

In addition to the above, other fasteners are manufactured to NAS Standards, such as Jo-Bolts (a trade name for internally threaded three-piece rivets) available as part of NAS 1669 / 1670 / 1750 / 1751 series, clamps like those of NAS1922 / NAS1924 series from stainless steel, or flat washers under NAS 1149 / NAS1149L series superseding respective AN 960 / AN 960L washers. 

Sourced from quality manufacturers, an extensive collection of Aerospace / Military and Industrial (Commercial) fasteners are offered either as OEM parts of their respective manufacturers or as parts of our own labelled (AVIATIONEU NEW ERA) product lines, in different materials, finishes, and sizes in Inch or Metric systems. Structured in different series based on the standard they conform they can be supplied in pieces but also in packs for convenience & economy where the number pieces per pack is indicated after the letters "PK" in the product SKU. Appearing prices are always for the used unit of measurement each time.