Type 19W4 Galvanized Welded Steel Grating. Nominal Width is 3 feet. Nominal Length is 4 feet. Composed of 21 1-1/4 x 3/16 inch bearing bars on 1-3/8 inch Center spacing and 1/4 inch square twisted crossbars at 4 intervals beginning 2-inch from end. Approximate weight 109 pounds. 9/16 inch diameter holes on both sides through the first two bearing bars at 4 5-3/4 42-1/4 and 44 inches from one end. Galvanize after fabrication per ASTM . Refer to ATC drawing SSST-03-08.