TU Series - Utility Carts & Tables - These all welded units include back and side stops on shelves to prevent parts and other items from rolling off. Casters: Shipped standard with floor pads or optional (4 swivel) 3" or 5" soft rubber casters. Capacity: 3" casters 300 lbs., 5" casters 500 lbs. Options: Wheel brakes on casters.