Frame and support: 1″ square aluminum tubing with 0.063″-thick wall. Gussets: Each frame and cross support junction shall be joined with a two-piece, die-stamped 0.100″-thick aluminum gusset, riveted to the tubing frame and cross support. Reinforcing bar: 1″ square tubing, at middle of height, between frames, for added rigidity. Tray slides: 0.100″-thick aluminum formed to 3 7/16″ wide lip with a beaded edge, for strength and minimum friction. Slides are riveted to frame. Casters: 5″ diameter NSF-approved, non-marking rubber tired wheels on swivel stem plated casters.