Follow taper taps are designed for safe repair of damaged original glow plug thread by retaping the thread for setting the insert. In the front part of taper tap there is a guiding tip in the form of glow plug body, original size of original thread, retracting the taper tap into the material, cutting blade, new thread size for insert. Taper tap body ended with hexagon for possibility of using the socket, extension in combination with ratchet.