<p>A fitting (1; 100) comprising an outer body (10; 110) and an inside gripper element (24; 124) suitable for blocking the extremity of a pipe (2). The gripper element comprises a terminal edge (30) on which can be exercised an axial force for moving the gripper in an advanced release position. On said terminal edge is fitted an annular protection element (40) comprising an inner lipped portion (42) extending in a radial direction towards the inside of the axial cavity of the outer body of the fitting so as to interact with the outer surface of the pipe. The outer body also comprises a cylindrical terminal portion (34) extending in an axial direction at least until it surrounds said protection element (40) so that the terminal edge of the gripper element is only accessible by means of a special tool.</p>