Abstract: The present invention relates to a pipe joint for connecting a piping comprising a cylindrical body with both ends open and a connecting part to a socket, the socket having a tapered part on the internal circumference and diminishing in diameter toward the open side, one end of the socket attached to the connecting part of the body and the other end of the socket being as the pipe inserting port and, an insert provided to the body in a way to slide freely within a certain range and having a free end facing the pipe inserting port, and a collet placed between the internal circumferential face of the socket and the insert in a way to advance and retreat freely.