[NU9]

Originally Posted by wrench68

This is exactly how I've been doing it for twelve years now. I sharpen the shank end of the drill on a piece of 600 sandpaper on a flat stone plate, then put it in a pin vise, then scrape the slot. Matts67 is right that the drills for the two plain strings are too fragile for practical use. After breaking about two dozen of each, I now use pieces of plain steel string one size larger than target, e.g., .013 for a .012 slot, and .017 for a .016 slot. Sharpen just as a drill, and hold in a pin vise, just as a drill. These are a little flexible, so keep the amount of exposed wire as short as you can get away with.

Besides successfully getting the job done, the bottom of the slots are perfectly radiused to match the string.

This is interesting! Thanks for sharing. So you actually just use the sharpened tip and scrape?