Wapometal

Wapometal (ワポメタル) 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 the metal that turned him from a homeless bum into a very wealthy CEO of a toy company. His Wapometal toys are so successful, the World Nobles granted him a new kingdom as a reward.

Franky used Wapometal for his Iron Pirate Franky Shogun. It appears to be 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

 * Since Wapol's cover story was not added in the anime, it is currently unknown how this metal will be introduced in the anime prior to Franky citing its use.