The argonite chainbody (Tier 7) is an item that can only be obtained and used while Dungeoneering. It requires level 60 Defence to wear. It may be picked up from the table at the beginning of a dungeon, obtained as a monster drop, or produced using the Smithing skill.
It can be produced by using 3 argonite bars with a hammer on an anvil, requiring level 66 Smithing and granting 201 Smithing experience.