Zach, that must be big nick or a very abused edge. Next bet is somthing electrical with a belt of sorts or a disc on a hand held grinder. Hard steal is tough on the file. I some times wonder just what hardness is best, to hard-its time consuming to sharpen and possibly brittle, to soft-won't hold an edge. I have found a nice middle ground for most of my tools, I keep trying new(old) tools from the antique tool places, to find one of the correct hardness, ax, draw knife, adze etc.. One of my favorite axes I use is sharpened only with a file, no hard spots, and stays sharp through two frames of use, the steal actually becomes polished with use and is still sharp, maybe it's charmed. So, if this is an ax that feel nice in your hands spend the time getting a sharp edge, with what ever means possible, or keep trying different tools till somthing somes around. Good luck, and Merry Christmas etc. I also have re-shaped the heads of some of my axes and then re-tempered them to a hardness of my likeness, it was a tricky process to say the least. Tim