Disappointing. The accuracy of these drills is not very good: 0.3-0.27, 0.35-0.34, 0.4-0.37, 0.45-0.43, 0.5-0.43, 0 .55-0.056, 0.6-0.58, etc. Close but not exact. I would return them except I can find sizes in the group to use. I don't think you should expect much for β¬12.