Nes, ThreadMate™ external thread repair tool

For home use. Hand tool to quickly clean & restore external threads. Installs to the thread diameter by rotating the knob, after which the tool is rotated around the bolt / stud. Automatically adjusts to the thread pitch since the blades are guided by chasing undamaged sections of the threads. Compatible with M4 to M13 or 5/32" to 1/2" diameter threads.