Iron Chest

The Iron Chest is an upgraded version of the standard Chest. It has 54 slots which is 18 more than a Standard Chest and 9 more than a Copper Chest. 54 slots is equivelant to a double Standard Chest. In addition to crafting it, you can also right click on a Copper Chest with a Copper to Iron Chest Upgrade to upgrade it to an Iron Chest.

Recipe
Refined Iron can also be used, however it provides no bonus and is slightly more costly but usefull if no normal iron can be obtained.