Park Tool Frame Tap (TAP-7)

Works perfectly for cleaning up those tiny derailleur threads, though I wish the handle was a bit longer for more leverage. Saved me from replacing a hanger on an old frame, so definitely worth having in the drawer.

The knurled handle gives a solid grip, making it easier to apply steady pressure when chasing those tiny M3 threads. It did the job cleaning up a slightly damaged hole on my frame without any issues. Only wish it came with a small case for storage.

Used it to clean out some stubborn M3 threads on an old frame, and it cut through the gunk smoothly without damaging anything. Only minor complaint is the handle could be a bit longer for more leverage, but it did the job perfectly.