Steel

Steel is a alloy. It is one of the strongest metals on Earth. Superman is often referred to as the Man of Steel, because of his awesome super strength and invulnerability. Although technically Superman is far more powerful than steel.

Marvin had a Superfriends wristband that was made of steel. While on Mystery Mountain, his wristband was caught in a magnetic field, due to the powerful magnet known as the Shamon U, which was created by Doctor Shamon.

Appearances
Super Friends
 * Season 1: The Shamon U