EMT can be made of galvanized steel, aluminum or even stainless steel. I expect the FIRST used steel for strength and weight considerations. I checked through the drawings and they list it only as EMT.
Electrical metallic tubing (EMT), sometimes called thin-wall, is commonly used instead of galvanized rigid conduit (GRC), as it is less costly and lighter than GRC. EMT itself may not be 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. Like GRC, EMT is more common in commercial and industrial buildings than in residential applications. EMT is generally made of coated steel, though it may be aluminum. from (wikipedia search)
I highly doubt it is stainless as someone posted on First Forum. Anyone know for sure?
