For helical coil wire screw thread insert taps * Tapered square shank fits into manual brace tools and drivers handles for added cutting pressure * Threads per inch need not be specified as Tap Extractors will fit both NC and NF taps * Hardened steel fingers of Walton Tap Extractors fit in the flutes of a broken tap to back it out simply and safely * When fingers become bent or broken or are too short for further use, replacement fingers are available