Can lid

A can lid, comprising:

• an opening piece enclosed by a score line on a panel portion;
• and
• a tab attached to the opening piece and configured to open the can lid by rupturing the score line and detaching the opening piece from the panel portion, wherein
• the score line is formed into a closed circle to be ruptured along a circumference of the panel portion,
• a rivet is formed in a vicinity of the circumference of the panel portion,
• the tab comprises an installation portion that is attached to the rivet, a finger grip portion that is situated closer to a center of the opening piece than the installation portion, and a nose portion that is situated on an opposite side to the finger grip portion at a radially outer side of the score line,
• a portion of the panel portion underneath the nose portion serves as a support section that supports the nose portion from below,
• an outer circumferential bead is formed on the radially outer side of the score line to enhance a bending stiffness of the support section,
• the outer circumferential bead includes end portions situated on both sides of the support section in a circumferential direction of the panel portion,
• the outer circumferential bead is formed along an outer circumference of the score line while being protruded toward an outer surface of the panel portion,
• the score line includes a main portion, a marginal portion extending in the vicinity of the rivet, and a connecting portion that connects the main portion to the marginal portion while being curved,
• the marginal portion is located circumferentially inward with respect to the main portion so that the support section is radially wider than a remaining section of the panel portion at the radially outer side of the score line,
• a chuck wall is formed entirely along an outer circumference of the panel portion,
• a residual ring portion is formed on a portion of the panel portion between the score line and the chuck wall, from which the opening piece is detached,
• the outer circumferential bead is formed on the residual ring portion while curving along the score line and protruding toward the outer surface of the panel portion,
• a flat portion of the residual ring portion of the panel portion between the end portions of the outer circumferential bead is the support section, and
• the nose portion of the tab contacts an upper surface of the support section tightly.