Tie Down Galvanized Trailer Bunk Brackets Tie Down Heavy duty 11 gauge trailer bunk brackets have been designed to support 2 lumber bunk boards that have been placed on edge. Trailer bunks are generally made from pressure-treated pine, or for more durability, hardwoods such as oak, or even cypress. Alternative include man-made products such as composite boards like the kind used in outdoor decking. Whatever product your trailer bunks are composed of, it is important to have tie down galvanized t