An octagonal bulk bin has sidewalls, end walls and diagonal corner panels interposed between adjacent sidewalls and end walls. Major bottom flaps are foldably joined to a bottom edge of the sidewalls, minor bottom flaps are foldably joined to a bottom edge of the end walls, and diagonal bottom flaps are foldably joined to a bottom edge of the diagonal corner panels. A cut separates each major bottom flap from an adjacent diagonal bottom flap, and a web panel connects adjacent side edges of the minor bottom flaps and diagonal bottom flaps. According to one aspect of the invention, each diagonal bottom flap, web panel, and portion of an adjacent major bottom flap are crushed. According to another aspect of the invention, differently shaped notches in a free edge of the minor flaps form locking tabs that are engaged in slots near a free edge of the major flaps.