Can manufacturing method, can manufacturing device, can, and can manufacturing tool set

A method for manufacturing a can comprising:

• forming a shoulder reduced in a diameter toward a side of a mouth of the can on a side of an upper end of a cylindrical body of the can in a can axis direction, wherein the shoulder has an inclination angle of 10° to 50° between a surface formed by extending the shoulder to a side of the body and the body, and a thickness of 0.1 to 0.3 mm,
• inserting an inner roll into the can from the mouth, wherein the inner roll comprises a shaft serving as a rotating axis of the inner roll and a receiver connected to the shaft at a bottom of the inner roll, and the receiver, has at least one of a concave portion and a convex portion, has a maximum outside diameter smaller than an inside diameter of the mouth, and has an external shape of a bevel shape along a shape of the shoulder;
• receiving the shoulder inclined at said inclination angle from inside with the receiver of the inner roll;
• pressing the shoulder from outside with an outer roll, wherein the outer roll has at least one of a concave portion and a convex portion corresponding to at least one of the concave portion and the convex portion provided on the receiver of the inner roll;
• and
• forming a three-dimensionally shaped portion on the shoulder by rotating the inner roll and the outer roll relative to the can, in a state in which the receiver of the inner roll and the outer roll clamp the shoulder from outside and inside.