Leadwoods were Deepwoods trees with extremely heavy wood. They were of the third order of buoyancy, and thus their weight remained constant at any temperature. Leadwood lumber was used to in the construction of heavy objects, such as the hull weights of Sky Ships or the bullets of Phraxmuskets and Phraxpistols. During the events of The Last of the Sky Pirates, Rook, Magda Burlix, Stob Lummus, and Hekkle rested in the branches of a leadwood tree while traveling to the Free Glades.