Abstract: A threaded connection structure for rotatably connecting and disconnecting adjoining members including a female member having annular internal pitched threads and a male member for threading into the female member having outer threads complemental to the threads of the female member with raised areas along the axial faces of the threads of one of said members to cause areas of concentration of unit pressure between the threads so that unwanted rotation and unwanted unthreading is prevented. A flange is provided on one member to engage a shoulder on the other member for continued axial surface pressure of the raised areas.