Iron chests are made by surrounding a chest with iron bars. They work exactly like normal chests. However, they can not be set on fire and must be destroyed with a stone pick or above. Because they can't be set on fire (and would naturally have a higher explosive resistance as a result of being iron), they would work well as (open) storage in the Nether as ghasts and lava won't be able to destroy the chest. They also would not be destroyed by lava which makes them grief resistant and prevents you from losing everything upon accidently setting your wooden floor on fire.
you mean like it being textured with one of the combo wheel locks on the front? that would be cool.