Abstract: Work surface extensions for tool storage units comprising a horizontally disposed housing adapted to be located between a pair of tool boxes, the housing being of a rectangular configuration positionable in a generally horizontal plane with a periphery generally corresponding to the periphery of adjacent tool boxes above and below, a pair of apertures, one on each side of the housing, the apertures being located at varying elevations with respect to each other, with a chamber formed within the housing and being accessible through the apertures and a pair of reciprocable members, the reciprocable members being of a planar configuration in the form of rectangles, each of the members being positioned through one of the apertures, each of the members having a first work surface on one side and a second work surface on the other side, each reciprocable member movable in a generally horizontal plane between an extended orientation wherein the majority of the work surface is exterior of the housing extending through