Lid for containers of substances and container of substances comprising said lid

Lid for a container made of metal and able to contain a substance, comprising:

• a closing element defined by a line of incision provided with a front portion,
• an opening lever disposed astride the line of incision and comprising a fulcrum front end disposed at the front of the front portion, and an intermediate region provided with a flexible tongue attached to the closing element,
• a mechanical element configured to attach the flexible tongue mechanically to the closing element, and provided with an upper abutment head, which is configured to cooperate with said flexible tongue and is delimited peripherally by an external periphery,
• a central reinforcement and stiffening stud protruding from the closing element,
• wherein said mechanical element is disposed essentially tangent to the front portion of the line of incision such that said external periphery of the upper abutment head is aligned orthogonally to said line of incision;
• wherein the front portion of the line of incision includes an outwardly protruding portion that extends toward the fulcrum front end of the opening lever to a zone where pulling and lifting of the lid starts;
• wherein the line of incision includes a radius portion and is made on a closing wall of the closing element;
• and
• wherein the protruding portion has a length and a maximum base width and the closing element has a maximum width, wherein a first ratio of the maximum base width of the protruding portion to the maximum width of the closing element ranges from about 0.18 to about 0.23, and wherein a second ratio of the length of the protruding portion to the radius of the closing wall ranges from about 0.15 to about 0.20.