Abstract: This sealing device for a cylindrical metal pack having a total opening, of the type comprising a recipient and a pressed-out cover and in which the inner peripheral surface of the opening of the recipient, which is devoid of an inner radial flange, cooperates directly with the outer cylindrical surface of the cover, comprises at least one partly O-section sealing element (11, 12) of a copolymer resin adhered in at least one cylindrical groove (9, 10) provided in the region of the recipient and/or the cover in which occurs a rubbing between the cooperating parts of the inner wall (8) of the opening of the recipient and of the outer peripheral wall of the cover when the cover (5) is placed in position and removed.