For more products catalog please contact our company. Rigid steel conduit (RSC) is a listed threaded metal ... . Threads on the uncoupled end are covered by industry color-coded thread protectors which protect the threads, keep them ... clean and sharp, and aid in trade size recognition. Rigid metal conduit is available in trade sizes 1/2 ... 1, 2, 3, 4, 5, and 6 are color-coded blue, trade sizes 1/2, 1-1/2, ...