Iron bamboo (Before the Fall Manga)

Kurogane Take (黒金竹) is the general and primary material used for crafting Military weapons, namely the vertical maneuvering equipment. Iron Bamboo is notably made out of iron ore absorbed from the ground, however the components of this special iron are unknown. Granted, the iron in the bamboo is possibly part of a brand new alloy. Unlike other metals, Iron Bamboo has the most potency when used against Titans, being the only known metal to-date known able to cut through a Titan's flesh. Iron Bamboo is exceptionally sharp when molded, and it is an incredibly strong plant, as shown when Jorge Pikale attempted cutting a stalk in half with his iron sword, but failing.

Development
Iron Bamboo was developed approximately 85 years before the fall of Wall Maria. It played a part in the military forces then by providing utility for the flawed invention called the "Device" at the time. Iron Bamboo was specifically used for the wiring and blades of the equipment. Additionally, Iron Bamboo can also be incorporated in other objects, such as Sharle Inocencio's knife. Initially, this "Device" had mainly been put to use by the Survey Corps, as they were the only ones who only needed to use it outside the walls.