RECTANGULAR CAN MANUFACTURING METHOD

To provide a rectangular can manufacturing method by which an angle between a step surface of a step provided on a rectangular can body and an inner wall surface of the rectangular can body can be so made as to be closer to 90 degrees.SOLUTION: In a step formation process, a die 310, which is formed on an outer wall surface side of a side wall forming a step part, and a mandrel 410, which pinches the side wall between itself and the die 310 on a bottom side of the inner wall surface forming the step part with respect to a formation part of the step part, and a punch 420, which presses a side of the inner wall surface forming the step part which is opposite to the bottom side with respect to the formation part of the step part, and compresses the side wall between itself and the die 310, are used, and the step part is formed by repeating plural pressing operations by the punch 420.SELECTED DRAWING: Figure 3 【課題】角形缶本体に設けられる段差の段差面と角形缶本体の内壁面とのなす角度を、より９０度に近付けることを可能とする角形缶の製造方法を提供する。【解決手段】段差形成工程においては、段差部を形成する側壁の外壁面側に設けられるダイ３１０と、前記段差部を形成する内壁面のうち該段差部の形成部よりも底部側においてダイ３１０との間で前記側壁を挟み込むマンドレル４１０と、前記段差部を形成する内壁面のうち該段差部の形成部よりも前記底部側とは反対側を押圧して、ダイ３１０との間で前記側壁を圧縮させるパンチ４２０と、を用い、パンチ４２０による複数回の押圧動作を繰り返すことで前記段差部を形成することを特徴とする。【選択図】図３