Abstract: The casing of a file shipping and storage container incorporates a reinforcing member along a pair of opposite walls at an end opening in which an external leg portion forms a right angle with a flange portion at a juncture that is smooth and uninterrupted and in which an internal leg portion forms a juncture with the flange portion that includes a row of aligned, lengthwise, longitudinally spaced-apart slits forming a bending line.