Western Tube 21 5IMC 10' x 1/2" Intermediate Metallic Conduit with Yellow End Cap IMC is manufactured as a cross between EMT and rigid metal conduit (RMC). A slightly thinner gauge than RMC, IMC is light but strong. It has the same electric-resistance welded tube-making process as EMT, but it is threaded like RMC, so the same couplings can be used for both. Like all of our electrical conduit, it is protected by zinc and organic coatings inside and out, and is thoroughly tested for bendability and threadability before being shipped.