The known can seamer in which a can drum filled with liquid and having a can lid placed on the opening at the top is subjected to seaming work by means of seaming rolls and a seaming chuck, is improved so that a replacement time for the seaming rolls and the seaming chuck in the case of changing the diameter of the cans can be greatly shortened. The improvements reside in that a seaming lever having the seaming rolls mounted thereon and the seaming chuck are respectively connected to the bottom end portions of a seaming roll shaft and a rotary cylinder via splines or serrations, and the seaming lever and the seaming chuck are integrally connected by means of a connecting bracket.
