The screw capsule comprises two parts, a) an insert (3) with a so-called internal head (30) and an internally-threaded skirt (31) and b) a metallic shell (4), comprising an external head (40) and an external skirt (41), said capsule being typically provided with a sealing means (5), a tamper-protection means (6) and a means for first opening (7), characterised in that said external skirt (41) comprises at least one piece (42), typically cylindrical, of height (H1), diameter (D1) corresponding to the neck (2) for sealing and at least one radially-expanded section (43), of height (H2), within a circle of diameter D2>D1, such as to form an annular radial cavity (48). The above offers the advantage that the expanded section (43) particularly facilitates the manipulation of said capsule (1) and the rotation thereof with relation to the neck (2) for opening/closing said container by unscrewing/screwing up said capsule (1) on said neck (2).