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. - Economical choice for home use - Single cutting blade; hardened HSS tool steel - Auto guided by existing threads - Removes rust and burrs - Automatically chases good threads to repair / re-groove damaged sections - For any thread diameter; inch or metric from M4 to M13 or 5/32" to 1/2" diameter threads - Hand tool - For any pitch - For right or left-hand threads