Thomas & Betts C-Style Conduit Body Iron

Four trade sizes: 3/4 inch (C75M-TB), 1-1/4 inch (C125M), 1-1/2 inch (C150M) and 4 inch (C400M). Order by the trade size of the rigid or IMC conduit it is landing on, since the hubs are threaded to that size.

No. The Thomas & Betts C body has threaded hubs for rigid or IMC conduit. For EMT you need a combination body with set-screw or compression connection, such as the Crouse-Hinds C15MTC-6 Condulet Type C combination EMT body.

Both are Type C conduit outlet bodies in the 1-1/2 inch size range, so they serve the same purpose: a straight-through pull and splice point in a conduit run. The difference is in the hub style. The Thomas and Betts C150M is a threaded malleable iron C body sized 1-1/2 inch for rigid or IMC conduit. The Crouse-Hinds C15MTC-6 is a Condulet Series 5 combination EMT body, meaning its hubs are built to take EMT as well. If the run is threaded rigid conduit, the T and B C150M matches the raceway directly; if the run is EMT, confirm the hub style before swapping.

The Thomas and Betts C-style bodies, including the C75M-TB in 3/4 inch and the C125M in 1-1/4 inch, are malleable iron Type C bodies intended for threaded conduit hubs. For an EMT run, a combination EMT body such as the Crouse-Hinds C15MTC-6 Condulet Series 5 is built to accept EMT at the hub. Keep the body type the same either way: a C body gives you a straight-line access opening, so the swap is about hub style, not about changing the geometry of the run.

Malleable iron. That is the heavier, threaded-hub body commonly specified with rigid steel and IMC; if your spec calls for copper-free aluminum to match an aluminum rigid system, this is not the matching material.

The Thomas & Betts C body is the body casting itself. Covers and gaskets for conduit bodies are ordered separately and sized to the body, so plan on a cover (and gasket where the location requires it) to close the opening.

No. The C15MTC-6 Condulet is a 1-1/2 inch class combination EMT Type C body. For a 4 inch opening, the Thomas and Betts C-style line covers it with the C400M in 4 inch malleable iron, and the same family also runs 3/4 inch, 1-1/4 inch, and 1-1/2 inch if you are standardizing a facility on one body style across several trade sizes.

No, covers are size-specific. Each trade size of the C body (3/4, 1-1/4, 1-1/2 and 4 inch) takes its own cover, so a facility stocking spares needs one per size in use rather than one universal cover.

A C body gives you access to pull conductors, and it is a common inline access point in a rigid or IMC run. Whether you can splice in it depends on the body having adequate volume for the conductors and splices under the NEC rules your inspector applies, so size the body and conductor fill accordingly.