GearWrench 2249D External Thread Restorer File SAE 9, 10, 12, 16, 20, 27, 28, 32 Pitch The GearWrench 2249D External Thread Restorer File SAE 9, 10, 12, 16, 20, 27, 28, 32 Pitch quickly restores threads with durable, fast cutting teeth. Used to restore worn or damged external threads on bolts and pipes, the GearWrench 2249D External Thread Restorer File SAE 9, 10, 12, 16, 20, 27, 28, 32 Pitch files both right and left hand threads.