Thread Repair File

Restore damaged external threads on studs, bolts, screws, plumbing pipe, and pipe fittings. Restores rusted and corroded fasteners. Doubles as a screw pitch guide. Length 8-1/2" x 7/16".No. 177-1: Thread pitches: 11, 12, 13, 14, 16, 18, 20, 24 threads per inchNo. 177-2: Thread pitches: 9, 10, 12, 16, 20, 27, 28, 32 threads per inch