National Stock Numbers (NSNs) serve as the backbone of military and aerospace supply chains by providing a uniform system of part identification across suppliers, platforms, and nations. Since procurement frequently spans multiple aircraft systems with unique technical requirements, NSNs are engineered to create a structured cataloging process that minimizes sourcing errors and ensures greater consistency. In this blog, we will explore how NSNs support procurement by standardizing operations across systems, cover the challenges they introduce, and delve into their specific applications for aircraft components.