This is galvanized water pipe, it will dull out a little over time but will not rust except at the threads which will need some treatment to prevent rust.

awesome, thanks! I'm not even sure rust at the threads is a down-side, but I like a smoother bar to run a hand along.

you can use black pipe as well but it requires a lot of degreasing and tends to be marred up by manufacturing and handling. often getting a custom made 1-1/4 tube rail from a fab shop can be pretty competitive when you consider the cost of all the pipe fittings and the labor, especially if you don't powder coat and just finish with some wax or laquer. Every commercial and multi family building has a pile of them so the shops get good at it.