This is a hobby, not a precision machine shop. I routinely sharpen HSS drills and put the proper rake on them down into the sixties. If your #50 drill cuts a thousandth oversize because you got the drill lopsided it just means the tap goes in easier. That is very helpful for crankpin screws, because they are 0-80 usually, and the number 56 drill, when sharpened, might cut enough steel out of there to save your eight dollar tap. Most shops use #55 for those threads - works fine. My locomotives have hundreds of tapped holes in them and they do not fall apart.
But buy new drills - it helps keep the costs down for those uf us with limited tool budgets.
