TWIST-A-NUTâ„¢ Tapping tool forms new threads, re-forms burred threads and cleans out obstructions. Reversible, high-carbon tap with three clearly marked thread sizes on each end. Includes: 6-32, 8-32 and 10-32 on one tapping side, 10-24, 12-24 and 1/4-20 on the other.