Abstract: An instrument having two branches such as a pair of scissors, or the like. The two branches thereof are connected with a coupling element, which is attached to one of the branches and extends through a hole in the other branch. The coupling element has a locking body situated on the outside of the other branch. Both the locking body and the hole are out of round so that the locking body can be brought through the hole in a certain angular position but not in another. According to the invention, the coupling element is screwed into the first branch. Furthermore, the locking body has a shape that is adapted in such a way to the shape of the hole that the coupling element can be turned by means of the second branch.