This document provides guidance for the following topics of stay cables of cable-stayed bridges: (a) main tensioning unit (stay cable); (b) sheath. The stay cable consists of a parallel steel-wire bundle encased in a polyethylene sheath and then filled with cement grout. The cable has been inspected many times with no sign of corrosion. The first adoption of this system in the United States was the Pasco-Kennewick Bridge completed in 1978.