first back member 6 the sheet metal connector 4 is preferably made from cold formed 14 gauge galvanized sheet steel preferably the first side edge 23 of the seat member 18 is integrally connected to the bottom edge 16 of the first side member 11 at a first juncture 25 of between 95 and 110 degrees between the upper surface 21 of the seat member 18 and the inner surface 13 of the first side member 11 preferably the bottom edge 31 of the second side member 26 is integrally connected to the second side edge 24 of the seat member 18 opposite the first side member 11 at second juncture 32 of between 95 and 110 degrees between the upper surface 21 of the seat member 18 and the inner surface 28 of the second side member 26 preferably the first side edge 23 of the seat member 18 is integrally connected to the bottom edge 16 of the first side member 11 at a first juncture 25 of 103 degrees between the upper surface 21 of the seat member 18 and the inner surface 13 of the first side member 11 preferably the bottom edge 31 of the second side member 26 is integrally connected to the second side edge 24 of the seat member 18 opposite the first side member 11 at second juncture 32 of 103 degrees between the upper surface 21 of the seat member 18 and the inner surface 28 of the second side member 26 the stiffening embossment 12 in the first side member 11 preferably is elongated and embossed into the inner surface 13 of the first side member 11 to a depth equal to the thickness of the.