I think i need a diamond file but I'm not sure. I've been teaching myself how to fix pocket knives and fixed blade knives. After a tip breaks off I reprofile the blade make it look like a knife again then thin if needed and sharpen. I got a knife recently that was sharpened toward the tip much heavier then the handle. The guy wants me to put a sharpening choil on it and fix the blade. None of my files will cut this blade though. I only need it for this one knife so i don't want to spend a lot of money on a file. Are the 10 dollar diamond files on Amazon good enough to do this? Would i be better off buying a single round file if so what brand. The steel of the knife was aus 8 I believe. I'm not equipped for annealing and heat treating nor do i have a belt sander. I'm very basic hobby level.