Caulking die, caulking tool, method for manufacturing caulking joint using them

A caulking die, comprising:

• an upper surface;
• a lower surface;
• and
• an end surface being connected to each of the upper surface and the lower surface,
• wherein the end surface comprises a first protruded part including a first top portion, a recessed groove, and a second protruded part including a second top portion in sequential order from the lower surface side toward the upper surface side,
• wherein the first protruded part, the recessed groove, and the second protruded part extend along a width direction of the end surface, and
• wherein a length of the second top portion is larger than a length of the first top portion, and a height of the second protruded part on a basis of the end surface is larger than a height of the first protruded part on the basis of the end surface in a cross-sectional view perpendicular to the width direction.