Question: what is the difference between emt and rigid?
Answer: Metal. Rigid metal conduit (RMC) is a thick-walled threaded tubing, usually made of coated steel, stainless steel or aluminum. Galvanized rigid conduit (GRC) is galvanized steel tubing, with a tubing wall that is thick enough to allow it to be threaded. ... EMT is generally made of coated steel, though it may be aluminum.