4 mm - 13 mm 60 Degree Replacement Blade for TM21 Internal ThreadMate

60° Replacement Blade for NES ThreadMate internal thread repair tool TM20. The blades are guided by the existing undamaged section of the thread, in order to regroove the damaged section. The blades can cut, clean and clear any thread. Thread materials with hardness lower than 45° Rockwell C, can easily be reformed.