An assembly for an axial turbomachine, in particular for an aircraft turbojet engine, comprising: - an annular row of stator vanes each with an airfoil and a radial head (34, 48, 54) containing a cylindrical journal, the vanes being orientable by pivoting about the axis of the journal; - an actuator for pivoting the vanes comprising a synchronizing ring and operating rods connecting the synchronizing ring to each of the vanes; - an outer shroud comprising a tubular wall (131, 231) and having an annular row of radial orifices for receiving the heads (34, 48, 54) of the vanes, the outer shroud comprising an axial outer shroud section, referred to as the upstream section, and an axial outer shroud section, referred to as the downstream section; each of the sections (130, 230) comprising an internal guide surface (129, 229) for the flow of gas from the turbomachine, the two sections (130, 230) being axially adjacent, each of the sections (130, 230) comprising: - an annular row of preferably semi-cylindrical radial half-orifices (132, 232); and - at least one flange (134, 234) positioned between two circumferentially adjacent half-orifices (132, 232); the half-orifices (132, 232) being arranged to allow each of the half-orifices (132, 232) of one section (130, 230) to be brought into axial and circumferential registration with a half-orifice (132, 232) of the other section (230, 130) to form the annular row of orifices, the at least one flange (134, 234) of one section (130, 230) being arranged to be axially and circumferentially matched with the at least one flange (134, 234) of the other section (230, 130); the sections (130, 230) being provided with an annular row of radial thickenings or bosses (133, 233) accommodating the half-orifices (132, 232), the radial thickeners or bosses (133, 233) being connected two by two circumferentially by the flanges (134, 234), one of the sections (130, 230), in particular the downstream section, having a seat for the vane orientation actuator, the seat comprising an outer cylindrical surface, characterized in that the head (34, 48, 54) of each of the vanes has an outer radial portion (36, 62, 64) on the side of the journal opposite the vane, the outer radial portion (36, 62, 64) extending circumferentially and/or axially by a dimension which is greater than the diameter of the corresponding orifice, and the section (130, 230) which comprises the seat has, on the axial side of the seat opposite the half-orifices (132, 232), only portions of smaller diameter than the diameter of the cylindrical surface of the seat. - an annular row of stator vanes each with an airfoil and a radial head (34, 48, 54) containing a cylindrical journal, the vanes being orientable by pivoting about the axis of the journal; - an actuator for pivoting the vanes comprising a synchronizing ring and operating rods connecting the synchronizing ring to each of the vanes; - an outer shroud comprising a tubular wall (131, 231) and having an annular row of radial orifices for receiving the heads (34, 48, 54) of the vanes, the outer shroud comprising an axial outer shroud section, referred to as the upstream section, and an axial outer shroud section, referred to as the downstream section; each of the sections (130, 230) comprising an internal guide surface (129, 229) for the flow of gas from the turbomachine, the two sections (130, 230) being axially adjacent, each of the sections (130, 230) comprising: - an annular row of preferably semi-cylindrical radial half-orifices (132, 232); and - at least one flange (134, 234) positioned between two circumferentially adjacent half-orifices (132, 232); - an annular row of preferably semi-cylindrical radial half-orifices (132, 232); and - at least one flange (134, 234) positioned between two circumferentially adjacent half-orifices (132, 232); the half-orifices (132, 232) being arranged to allow each of the half-orifices (132, 232) of one section (130, 230) to be brought into axial and circumferential registration with a half-orifice (132, 232) of the other section (230, 130) to form the annular row of orifices, the at least one flange (134, 234) of one section (130, 230) being arranged to be axially and circumferentially matched with the at least one flange (134, 234) of the other section (230, 130); the sections (130, 230) being provided with an annular row of radial thickenings or bosses (133, 233) accommodating the half-orifices (132, 232), the radial thickeners or bosses (133, 233) being connected two by two circumferentially by the flanges (134, 234), one of the sections (130, 230), in particular the downstream section, having a seat for the vane orientation actuator, the seat comprising an outer cylindrical surface, characterized in that the head (34, 48, 54) of each of the vanes has an outer radial portion (36, 62, 64) on the side of the journal opposite the vane, the outer radial portion (36, 62, 64) extending circumferentially and/or axially by a dimension which is greater than the diameter of the corresponding orifice, and the section (130, 230) which comprises the seat has, on the axial side of the seat opposite the half-orifices (132, 232), only portions of smaller diameter than the diameter of the cylindrical surface of the seat.