This teng tools tap and die set is ideal for repairing screw threads taps cut a thread on the inside surface of a hole creating a female surface which functions like a nut dies on the other hand cut a thread on a preformed cylindrical rod which creates a male threaded piece which functions like a bolt this 17 piece set contains 7 metric taps and dies of each dimension a tap wrench a die stock and a screw pitch gauge the tools are supplied in a handy storage tray the tttd17 tap and die set contai