I'm relocating my tower next month to my new home, and have to pour a new
pier footing for the tower.

Does anyone have a good online source for threaded rod?

Specifically, I'm looking for 3 pieces of 1 inch threaded rod, roughly 3' in
length.

Local supply sources don't stock anything that large, plus I would question
the quality of the rod they sell in terms of the softness of the steel. I
want to make sure I get the best quality I can buy up front.