Steel conduit fittings are designed to be compatible with specific types of steel conduits. The compatibility between conduit fittings and conduits depends on the size, threading, and the type of steel conduit used. Here are some common types of steel conduits and their corresponding fittings:
Rigid Metal Conduit (RMC): RMC is a heavy-duty steel conduit used for demanding electrical applications. It typically has threaded ends, and you'll need fittings that match the thread size and type. Common threads for RMC include National Pipe Thread (NPT) or National Electrical Thread (NEC).
Intermediate Metal Conduit (IMC): IMC is a lighter-weight steel conduit with threaded ends, and it uses the same threads (NPT or NEC) as RMC. Fittings for IMC are usually interchangeable with those for RMC.
Electrical Metallic Tubing (EMT): EMT is a thin-walled steel conduit that is typically not threaded. EMT fittings are designed to secure EMT conduit with compression couplings or set screw connectors, which do not rely on threading.
Galvanized Steel Conduit: Both RMC and IMC can be galvanized to provide corrosion resistance. Galvanized steel conduit fittings are used with galvanized conduits.
Stainless Steel Conduit: Stainless steel conduits are used in environments where corrosion resistance is critical. Fittings designed for stainless steel conduits should be used with this type of conduit.
Flexible Metal Conduit (FMC) and Liquidtight Flexible Metal Conduit (LFMC): These conduits are flexible and require specialized fittings designed for use with flexible conduits, which typically feature a mechanism to secure the conduit without the need for threads.
It's important to select conduit fittings that match the specific type of steel conduit you are using to ensure a secure and compliant installation. Using the wrong type of fittings or misaligning threads can result in unsafe or unreliable electrical connections. Always follow local electrical codes and manufacturer's recommendations when installing steel conduits and fittings.