A threaded connector including female thread and male thread. The female thread is symmetrically disposed on both ends of a coupling. The male thread is disposed at an end of a pipe. The female thread includes buttress thread. A torque shoulder is disposed in front of the buttress thread. The female thread is connected to the torque shoulder via a tool withdrawal groove. A protruding threaded segment is disposed on any one of a fourth to seventh tooth of the female thread to prevent high pressure gas from leaking.