Sub-assembly of external parts for timepiece or watch or a piece of jewellery

A sub-assembly of external parts for a watch or for a piece of jewellery, comprising, coaxially with a first component and a second component compressing together a sealing and friction joint, and interposed therebetween, a bolt securing them together by axially blocking said first component, and a lower surface of said bolt faces, in the assembled position, an upper surface of said second component, wherein said bolt includes a lower relief protruding axially from said lower surface towards said second component, wherein said lower relief is arranged to either complementarily cooperate with an oblong groove which is partially of revolution that said upper surface includes, and interrupted by a stopper limiting the angular travel between said second component and said bolt within a turn, or to constitute an angular stopper to an upper relief protruding from said on upper face of said second component and extending axially towards said bolt.