This specification covers the general requirements for rigid waveguide assemblies, hereinafter referred to as "assemblies"Intended Use: Rigid waveguide assemblies are intended for use as bends, corners, and twists in rigid waveguide transmission lines to facilitate permanent direction or field orientation changes in the transmission line. The waveguide assemblies herein specified are military unique because they must function within and withstand for prolonged periods worldwide military unique environments. Commercial electronic components are not designed to withstand such extreme environmental conditions. Military uniqueness is also due to the costs required to change fielded systems to accommodate other than these standard military components.