Abstract: A hinge with a left-hand side flap plate and a right-hand side flap plate, each of which has no tubular portion for receiving a shaft bar. Each side flap plate has on its end at least one shaft plate having at least one communication hole and at least one semicircular locking hole. The semicircular holes come in contact with each other to form a circular portion when the shaft plates of the right and left flap plates are fitted together. In this circular portion a ball having a washer is fitted. The shaft plates, communication holes and the ball are covered with core shafts communicating with the opposite surface of the shaft plates. The core shafts are made of synthetic resin or die casting alloy.