Metal lid for a container body, in particular for a container of the metal can type, said lid comprising (i) a central part forming a sealing central panel, and (ii) a peripheral part adapted to be secured to said container body, wherein said central part comprises a removable part delimited by a break-off line in the general shape of a parallelogram, and wherein said break-off line is consisted of two longitudinal sections (4 a) and two transverse sections (4 b), wherein said removable part of the lid is equipped, at one of the surfaces thereof, with a gripping member consisted of two parts (7 a, 7 b) through which a longitudinal axis passes: - a first part (7 a) secured to said removable part and a second part, the actual gripping part, wherein said first part (7 a) of the gripping member is secured at a junction angle (4 c) corresponding to the junction between a first longitudinal section (4 a 2) and a first transverse section (4 b 1) of said break-off line, which first longitudinal section (4 a 2) and first transverse section (4 b 1) of said break-off line each comprising two portions: (i) an upstream portion (4 a 21, 4 b 11) arranged at said junction angle (4 c), intended to be torn by an operation of initially pivoting said gripping member and (ii) a downstream portion (4 a 22, 4 b 12) remote from said junction angle (4 c), made up by the remaining length of said section (4 a 2, 4 b 1) and intended to be torn by a subsequent operation of pulling the gripping member, which downstream portion (4 b 12) of the first transverse section (4 b 1) of the break-off line extends such that, all along the length thereof, the tangents to it define an outer angle (α) greater than 45° with a straight line perpendicular to said longitudinal axis of the gripping member, wherein said outer angle (α) increases over the length of the downstream portion (4 b 12) of the transverse section (4 b 1) of the break-off line, starting from the upstream portion thereof (4 b 11), characterized in that the downstream portion (4 b 12) of the first transverse section (4 b 1) of the break-off line is of generally curved shape, divided into two parts: - a first part in the general shape of an arc of an ellipse, on the upstream portion (4 b 11) side, and - a second part in the general shape of an arc of a circle, for the connection with the second longitudinal section (4 a 1). - a first part (7 a) secured to said removable part and a second part, the actual gripping part, wherein said first part (7 a) of the gripping member is secured at a junction angle (4 c) corresponding to the junction between a first longitudinal section (4 a 2) and a first transverse section (4 b 1) of said break-off line, which first longitudinal section (4 a 2) and first transverse section (4 b 1) of said break-off line each comprising two portions: (i) an upstream portion (4 a 21, 4 b 11) arranged at said junction angle (4 c), intended to be torn by an operation of initially pivoting said gripping member and (ii) a downstream portion (4 a 22, 4 b 12) remote from said junction angle (4 c), made up by the remaining length of said section (4 a 2, 4 b 1) and intended to be torn by a subsequent operation of pulling the gripping member, which downstream portion (4 b 12) of the first transverse section (4 b 1) of the break-off line extends such that, all along the length thereof, the tangents to it define an outer angle (α) greater than 45° with a straight line perpendicular to said longitudinal axis of the gripping member, wherein said outer angle (α) increases over the length of the downstream portion (4 b 12) of the transverse section (4 b 1) of the break-off line, starting from the upstream portion thereof (4 b 11), characterized in that the downstream portion (4 b 12) of the first transverse section (4 b 1) of the break-off line is of generally curved shape, divided into two parts: - a first part in the general shape of an arc of an ellipse, on the upstream portion (4 b 11) side, and - a second part in the general shape of an arc of a circle, for the connection with the second longitudinal section (4 a 1).