A coupling is used to join two sections of conduit together, extending the length of a conduit run. It connects conduit-to-conduit and is available in various types, such as set-screw, compression, or threaded, depending on the conduit material and installation requirements. A connector, on the other hand, is used to attach conduit to an enclosure, electrical box, or panel. It provides a secure connection and often includes features for grounding or strain relief.

EMT couplings provide a conductive path for grounding and fault currents through their metal construction, which creates a secure connection between adjoining conduits. Compression couplings achieve this by using a tightened compression ring that securely clamps the conduit ends, while set-screw couplings use screws to press against the conduit, maintaining contact. Both types are designed to meet NEC requirements for bonding by ensuring low-resistance continuity, allowing fault currents to safely return to the grounding system. Some couplings also include additional bonding features, such as grounding screws or bushings, for enhanced reliability in critical installations.

Yes, there are universal couplings that can work EMT, rigid metal conduit (RMC), and intermediate metal conduit (IMC). These couplings are typically made from durable materials like zinc-plated steel or aluminum and feature versatile designs, such as threaded and compression components, to ensure compatibility with different conduit types. For example, some couplings have one side with a compression fitting for EMT and another with threads for RMC or IMC.

For high-vibration environments, heavy-duty couplings with locking mechanisms, such as compression couplings with locknuts or vibration-resistant set-screws, are commonly used. For hazardous locations, there are explosion-proof or hazardous-rated EMT couplings. These are typically made from steel or brass and are designed to meet specific standards, such as NEC Article 501 for Class I, Division 1 or 2 locations.