We have some inspectors that maintain that a galvanized rod must be 5/8" diameter. The Galvan rod is just a touch over 1/2" in diameter. Based on my research, with UL and NEMA, the Galvan rod does not have to be 5/8" and coplies with 250.52(A)(5)(b). even though it is a steel rod that has been galvanized.
