Steel Conduit
This information reflects our best understanding of product composition in 2015, with the exception of the following components that have since had their composition updated: Chromate Pretreatment (updated 2024).
Electric Rigid Steel Conduit (ERSC) is defined by the National Electrical Manufacturers Association as a "threadable steel raceway of circular cross-section designed for the physical protection and routing of wire conductors and use as an...
Electric Rigid Steel Conduit (ERSC) is defined by the National Electrical Manufacturers Association as a "threadable steel raceway of circular cross-section designed for the physical protection and routing of wire conductors and use as an equipment grounding conductor." There is no one ASTM standard for ERSC, but it is manufactured to ANSI standard C80.1 and UL6. According to these standards, ERSC is produced in nominal 10 ft lengths, with threaded ends and one coupling attached. The exterior surface is protected with a metallic zinc coating or alternative protection coating such as PVC while the interior surface is protected with a zinc or organic coating, such as a polyester powder coating. In order to protect the newly galvanized zinc from white rust, an additional chromium coating, most commonly trivalent chromium, is needed. Chromium coatings may also serve as a conversion coating which prepares the surface for paint adhesion. Most frequently, many specifications referred to hot dipped galvanization along with a hot dipped organic coating. Zinc and chromium coatings are assumed to be present on the interior and exterior surfaces of the conduit and polyester powder coatings are assumed to be present on the interior surface of the conduit.