Please note: All interim revisions for this edition available at time of your purchase will be included.

1 Scope
1.1 These requirements cover surface metal raceways and fittings for use in accordance with the National Electrical Code, NFPA 70.
1.2 Raceways of the following thicknesses are intended to enclose circuits operating at potentials not exceeding 600 volts between conductors:

a) Raceways that are entirely of metal at least 0.040 inch (1.02 mm) thick nominal and
b) Raceways consisting of nonmetallic covers on metal bases of the thickness indicated in (a).

Thinner all-metal raceways or raceways of thinner metal bases with nonmetallic covers are intended to enclose circuits operating at potentials lower than 300 volts between conductors.
1.3 These requirements do not cover cable trays, wireways or nonmetallic raceways.