When in physical contact for a long time, it can and will accelerate the healing factor of the wielder. It's more durable than steel but lighter than titanium. Once, Ryūken Senju used a net made of metal X to trap Shinzui Uchiha who was trying to escape using Kamui. Thereby, he came to the conclusion that, Metal X negates dimensional shifting that an Uchiha would be capable of. The name of the discoverer of Metal X on Earth has yet to be revealed but Ryūken was the one to put the metal to practical use. Ryūken states that the metal could be used to create armors and weaponry.