The present disclosure concerns an assembly of a turbomachine or of a combustion chamber test bench, generally including an annular outer housing, inside which a combustion chamber is housed, and a ferrule downstream from the housing. The ferrule may be attached to said housing by a connection comprising a radial flange rigidly connected to one of the housing and the ferrule, an annular groove being provided in the radial flange, and an axial tab rigidly connected to the ferrule or to the housing. The tab is generally housed in the groove, and the tab and the annular groove may be arranged relative to each other in such a way that, at assembly, they are in contact and centered relative to each another.