What are the three main standards used by fastener manufacturers?

Fastener manufacturers commonly refer to various standards to ensure the quality, reliability, and safety of their products. The three main standards recognized in the aerospace industry—AN (Army-Navy), NAS (National Aerospace Standard), and MS (Military Standard)—specifically address fasteners used in aircraft and aerospace applications.

AN specifications cover a range of fasteners designed for military applications, ensuring they meet rigorous performance criteria specific to aviation. NAS standards are established by the aerospace industry and provide guidelines for fasteners that are performance and safety-centric. MS standards include various military specifications that relate to materials and engineering practices across a wide range of components, including fasteners.

The other options listed reference various standards, but none combine the specific focus on fasteners as effectively as the combination of AN, NAS, and MS. This distinctive focus makes them particularly relevant for fastener manufacturers working within the aerospace sector.