Thomas & Betts FD12-TB 1/2 INCH, 2G-DEEP BOX, IRON, D-END

The FD12-TB is a two gang deep device box with 1/2 inch hubs, cast in iron. FD style boxes are the deeper version of the FS box, so there is more interior volume behind the device for conductors and splices. They are used on exposed conduit runs where a rigid, threaded-hub enclosure is needed rather than a sheet metal box, typically on walls, columns, machinery and outdoor or damp locations.

Dead end means the conduit hubs enter from one end only; the opposite end is closed. It terminates a conduit run rather than letting it pass through. If you need conduit to continue on past the box, you want a through feed FD box with hubs on both ends instead.

Yes. FD boxes are device boxes drilled for standard wiring devices, and this one is two gang, so it takes two devices side by side. Covers are the FD/FS style gasketed cover plates, which are ordered separately by device configuration (two duplex, two toggle, blank, or a mix). The box itself does not include a cover.

Both take the same devices and the same covers; the difference is depth. FD is the deep body, FS is the shallow one. Pick the FD, like this FD12-TB, when you are pulling several conductors through, landing a larger device, or need splice room. Go FS where wall clearance is tight and the wire count is low.

The body is iron, a cast metal enclosure. Being conductive, it has to be bonded like any metallic box; with threaded rigid conduit into the hubs, the raceway itself normally provides that path, and FD boxes include a grounding provision inside for an equipment grounding conductor.

Order by catalog number. This one is FD12-TB from Thomas & Betts: FD body, two gang, 1/2 inch hubs, dead end. The digit pattern in the number is what changes when you move to a different hub size or to a through feed body, so match the catalog number on the drawing rather than the description alone.