Speed Metal is a group of robots granted super-speed. They act as law-enforcement agents in John Fox's time.
When he went back in time, Speed Metal pursued him. Ruthless, they were not worried about civilian casualties. The Speed Metal robots were destroyed by Wally West to save John's life.
Speed Metal is capable of going at super-speed. They are made of a dense metal that cannot be vibrated through. They, however, are capable of vibrating through substances.