A rack for shelving consisting of upright posts and horizontal beams, connecting each between two upright posts, wherein said upright posts comprise. The upright posts include each at least one flank demonstrating one column of through gamma perforation doublets. The horizontal beams are either depth forming beams or width forming beams. The width forming beams include each at each of each extremity two rows of one doublet of fasteners adapted to fit with the gamma perforations so that the entire number of individual fasteners in those two rows of said perforations find each a matching perforation. The fasteners of the width forming beam are formed including each a cross recess of the width matching the width of the flank of the upright posts.