NAICS 336510 includes locomotives, freight cars of all types (boxcars, tank cars, flatcars, hoppers), passenger coaches, subway and light rail cars, and maintenance-of-way equipment. It excludes fixed rail infrastructure (track, signals, switches) and highway vehicles that may operate on rail under special configurations.

Rolling stock orders typically involve lead times of one to three years from contract award to delivery, driven by custom engineering, regulatory certification, and production scheduling. Importers and transit agencies must plan procurement well in advance, and any supply disruption — whether from trade remedies, material shortages, or manufacturing delays — can have significant downstream operational consequences.