Tony Stark's gray armor was built around an iron chest plate designed to prevent the piece of shrapnel he'd received in Vietnam from traveling to his heart and killing him. The armor, made from ordinary iron, provided protection from physical attacks, small arms fire, temperature extremes, some energy forms, and acid. Powered by flat linear armature DC motors (rechargeable via any electrical outlet), the exoskeleton boosted the strength of the wearer by about 10 times, and employed negative feedback for motion sensing. Air pressure jets allowed for extended jumps, but not true flight. Weaponry included a chest-mounted mono-beam (proton beam generator; useful range was only a few yards), a miniature hacksaw that extended from the gauntlet's fingertips, and magnetic turbo-insulators that allowed Stark to magnetically deflect metal projectiles or bring metal objects to him. Sensors consisted of a short-wave radio. All of the armor's devices and functions were manually controlled by the wearer. Stark constructed at least one updated, form-fitting version, still rigid, upon his return to the United States.

Iron Man quickly shed this armor in favor of the Mk. II armor, which was identical in Model but instead had a Gold finish to appear less intimidating.

Eddie March later wore the armor while he battled Ultimo.

In Other Media

Film

Iron Man (2008)

In the first Iron Man movie, Tony Stark (played by Robert Downey, Jr.) constructs the Mk. I armor while being held captive by the Ten Rings organization (rather than Vietnamese communists). Tony tricks his captors by falsely agreeing to build a high-tech Jericho Missile for them, but instead uses the parts they give him to construct a primitive suit, which he uses to escape. The suit is destroyed during Stark's trip, and the remains are later recovered by Obadiah Stane, who uses them as the basis for his new Iron Monger suit.

Television

Fantastic Four: World's Greatest Heroes

The Mk. I armor appears in the episode "Shell Games."

Avengers: Earth's Mightiest Heroes

The Mk. I armor appears in the episode "The Ultron Imperative," where Tony dons it after Ultron hacks into all of his other, more advanced armors.

It reappears in the episode "Powerless," where Tony is forced to wear it after a magic spell removes most of his tech and intelligence.

Video Games

• The Mk. I armor appears in Sega's Iron Man video game. It is worn in the first level, where the player must escape from captivity and defeat the Ten Rings terrorists.
• The Mk. I armor appears in Lego Marvel Super Heroes.
• The Mk. I armor appears as an alternate costume for Iron Man in Marvel Heroes.

Merchandise

• The Mk. I armor was featured by ToyBiz in the Marvel Legends Mojo Build-a-Figure wave.
• Hot Toys produced a figure of the armor for the first movie.
• The Mk. I armor was featured in Hasbro's movie toy lines for Iron Man and .
• The Mk. I armor was featured in Hasbro's Marvel Universe line.
• Dark Horse produced a statue of the Mk. I armor.
• Kaiyodo released a figure of the Mk. I armor for the Revoltech line.
• Beast Kingdom produced a toy of the Mk. I movie armor as well for the Egg Attack line.
• Jada produced a Mk. I movie figure.