Wapometal

Wapometal is a special kind of metal discovered by Wapol when he was turning garbage into toys during his mini-story, manufactured via his Baku Baku no Mi powers. It was this metal that turned him from a homeless bum into a very wealthy CEO of a toy company. His wapometal toys were so successful, the World Nobles granted him a new kingdom as a reward.

Franky used wapometal for his Iron Pirate Franky Shogun. It is a shape-memory alloy that can be restored to its preconfigured shapes, being used to create merger modes in the components of the Iron Pirate Franky Shogun.

Trivia

 * Despite the fact that Wapol's cover story was not shown in the anime, Franky cited the use of this metal when introducing the Iron Pirate Franky Shogun without any further elaboration on what was said in the manga.