Electrical metallic tubing (EMT) is a lightweight conduit that is used to encase electrical wires within a structure. Although there are several other piping materials available, this type is one of the more common choices by contractors because it is more cost-effective than comparable materials. Steel and aluminum are the two main choices used to make the tubing, and in many cases, it is also galvanized with zinc coating so that is will remain resistant to corrosion. Unlike many of the other options within electrical tubing, EMT does not thread together; instead, the ends are fitted to clamps.
This tubing is among the most popular choices for both indoor and outdoor use because it is the lightest steel encasement on the market. Since it is constructed from a premium metal, it controls the flow of electricity throughout the pathways that are created, and many regions actually specify that EMT must be used to meet building standards. Nonmetallic tubing is also much more vulnerable to moisture, which is dangerous around free-flowing electricity. Exposure to chemical vapors or protection from accidental blunt-force impacts are also reasons that this tubing is used; even light metallic plating is better than none at all.
Another reason why contractors use electrical metallic tubing over many of the other materials available is the ease of installation. Construction workers often have to function within a very confined space to install electrical tubing, and some of the bulkier alternatives are much more difficult to handle. Within crawlspaces or attics, this product can be installed quickly and efficiently, and the threaded clamps interlock for a secure connection. Since EMT is also somewhat flexible, it can be installed throughout other areas that would be otherwise impossible. An additional benefit is that since it is often galvanized, it is also suitable for installation it outdoor environments.
Electrical metallic tubing also has its share of drawbacks, and it is not recommended for every possible application. When a large series of wires is used, for example, a contractor may prefer to instead use rigid metal conduit (RMC) or galvanized metal conduit (GMC) to provide superior protection. Areas that require multiple bends and curves may be better-suited with flexible metallic tubing (FMT) or flexible metallic conduit (FMC), since they can be manipulated at almost any angle, yet still remain stable. Residential homes are not often wired with this form of tubing either; it is primarily used within commercial buildings.
