Abstract: A key for use with knock-down shelving units which can be fixedly assembled with the vertical posts of the unit before they're hoisted into vertical position and enables easy assembly of the horizontal beams therewith. The key includes a vertical shank with a pair of hooks projecting outwardly from the shank intermediate its ends and then upwardly in the form of a hook projection. The lower side of each hook adjacent the shank is provided with a downwardly opening notch which will wedgingly lock with the walls of the vertical post at the lower end of the slots therein. The lower side of each hook slopes downwardly from the shank to assist in assembly of the key with the vertical posts.