Three basic types of steel conduits are in use today: Rigid Metal Conduit, Intermediate Metal Conduit and Electrical Metallic Tubing.
Rigid Metal Conduit (RMC), also known as Rigid Galvanised Steel (RGS) or Galvanized Rigid Conduit (GRC), is a thick-walled threaded tubing, with a tubing wall that is thick enough to allow it to be threaded. It can be used in severe corrosive areas.
Intermediate Metal Conduit (IMC) is a steel tubing heavier than EMT but lighter than RMC. It is a great choice for outdoor applications.
Electrical Metallic Tubing (EMT), sometimes called thin-wall, is the most widely used nonflexible conduit, as it is less costly and lighter than RMC. EMT itself is not threaded, but can be used with threaded fittings that clamp to it. Lengths of conduit are connected to each other and to equipment with clamp-type fittings.
All the steel conduits should be supported at no longer than 10 feet of interval. The standard length is 10 feet.
All the cut ends must be reamed to remove any rough edges when the conduit is cut.
