John Henry Irons (Shaquille O'Neal) is a weapons designer for the United States military. When his project to create weapons that harmlessly neutralize soldiers is eradicated, he resigns in disgust. When he sees criminal gangs are using the weapons that he helped manufacture on the street, he uses his resources and his Uncle Joe's (Richard Roundtree) equipment in his junkyard to fight back against the man who's been selling them to those gangs: Nathaniel Burke (Judd Nelson). Irons forges himself a suit of armor and the weaponry necessary to carry out his war on crime and becomes the vigilante "Steel." Ultimately, Burke is arrested by the army and John Irons, Susan Sparks, Uncle Joe and Martin get together at Grandma Odessa's new restaurant.