Abstract: Joining piece that includes two parts fitted one inside the other and assembled together, and associated manufacturing method. The joining piece is for producing a mechanical joint between two elements, and includes a female part including a mechanical assembly portion and a receiving portion continuing on from the assembly portion, with the receiving portion being in the shape of an equatorial section of a sphere, and a male part including a mechanical assembly portion and an insertion portion continuing on from the assembly portion, the insertion portion being in the shape of an equatorial section of a sphere, inserted with clearance into the receiving portion and being retained in it, so that the male part is rotatably mobile in one or more degrees of freedom relative to the female part while being mechanically assembled with it.