The instrument (1) has shear-type side pieces (5, 6) connected with each other and comprising a gripping device (9) at its distal ends (7). The gripping device has gripping elements (10, 11) comprising a U-shaped arrangement at the distal ends. A hollow cylinder (19) is made of a metallic tube that is attached at one of the side pieces by a thermal process. The metallic tube has a continuous hole (21) for accommodation, guiding and extraction of an actuating tool (25) that is utilized for actuating an adjusting device (33).
