"Iron fire" is a phrase that does not commonly have an antonym, as it is a specific type of fire that is produced by burning iron. However, if we break down the phrase and look at the words individually, we can identify some antonyms. Iron can be seen as heavy, rigid, and durable. Therefore, antonyms for iron can be lightweight, flexible, or fragile. Fire can be seen as hot, bright, and destructive. Antonyms for fire can be cold, dim, and constructive. Though the phrase "iron fire" might not have a direct antonym, the words that make up the phrase can have their own opposite meanings.