A method for making corrugated core paperboard in which the edges of the facing sheets are rolled inwardly toward each other and tucked into the end of the corrugated core convolutions to form an enclosure thereof; including feeding the board along a path, slitting the end of the core by cutting or crushing the core along a line intermediate the facing sheets and rolling and tucking the end edges of the facing sheets into the slit, the apparatus including driven belts between which the board is fed along a path, a knife support along the edge of the path through which the edge of the board is fed and dies having edge engaging surfaces for rolling and tucking the ends of the facing sheets into the core.