For internal threads. 7-pc UNF (fine threads). Incl. 1/4″-28; 5/16″-24; 3/8″-24; 7/16″-20; 1/2″-20; 9/16″-18; 5/8″-18. Used to restore damaged internal threads. This are special threaded restoring taps that ensure a good result and they are safer in restoring threads than using regular thread cutting taps and dies. Regular cutters are sharper and can easily further damage existing threads. Packed in a re-usable clamshell package. USA made. Note: Not suitable for cutting new threads.
