34.10.00 Guideways/Railways
34.11.00 Rail Tracks
34.11.13 Track Rails 34.11.13.13 Light Rail Track 34.11.13.23 Heavy Rail Track 34.11.16 Welded Track Rails 34.11.16.13 In-Track Butt-Welded Track Rail 34.11.16.16 Pressure-Welded Track Rail 34.11.16.19 Thermite-Welded Track Rail 34.11.19 Track Rail Joints 34.11.23 Special Trackwork 34.11.23.13 Ballasted Special Track Rail 34.11.23.16 Direct-Fixation Track 34.11.23.23 Running Rail 34.11.23.26 Precurved Running Rail 34.11.26 Ballasted Track Rail 34.11.26.13 Track Rail Ballast 34.11.26.16 Track Rail Subballast 34.11.29 Embedded Track Rail 34.11.33 Track Cross Ties 34.11.33.13 Concrete Track Cross Ties 34.11.33.16 Timber Track Cross Ties 34.11.33.19 Resilient Track Cross Ties 34.11.36 Track Rail Fasteners 34.11.36.13 Direct-Fixation Fasteners 34.11.39 Track Collector Pans 34.11.39.13 Fiberglass Track Collector Pans 34.11.93 Track Appurtenances and Accessories