Metal Chest Upgrades

Each of the Metal chests can be upgraded by right-clicking them with the upgrade item (normal chest, too). Here is a list of the possible upgrades along with their respective crafting recipes.

Normal to Copper
The Normal to Copper chest upgrade is used to transform an already-placed normal chest into a Copper Chest without displacing the items inside. To use it, simply hold it in your hand and right click the chest you wish to upgrade it will change color and upgrade the chest size from 9x3 to 9x5.



Normal to Iron
The Normal to Iron chest upgrade is used to transform an already-placed normal chest into a Iron Chest without displacing the items inside. To use it, simply hold it in your hand and right click the chest you wish to upgrade it will change color and upgrade the chest size from 9x3 to 9x6. Refined Iron can also be used but provides no benefits.

Copper to Iron
The Copper to Iron chest upgrade is used to transform an already-placed Copper Chest into a Iron Chest without displacing the items inside. To use it, simply hold it in your hand and right click the chest you wish to upgrade it will change color and upgrade the chest size from 9x5 to 9x6.

Copper to Silver
The Copper to Silver chest upgrade is used to transform an already-placed Copper Chest into a Silver Chest without displacing the items inside. To use it, simply hold it in your hand and right click the chest you wish to upgrade it will change color and upgrade the chest size from 9x5 to 9x8.

Iron to Gold
The Iron to Gold chest upgrade is used to transform an already-placed Iron Chest into a Gold Chest without displacing the items inside. To use it, simply hold it in your hand and right click the chest you wish to upgrade it will change color and upgrade the chest size from 9x6 to 9x9.

Silver to Gold
The Silver to Gold chest upgrade is used to transform an already-placed Silver Chest into a Gold Chest without displacing the items inside. To use it, simply hold it in your hand and right click the chest you wish to upgrade it will change color and upgrade the chest size from 9x8 to 9x9.

Diamond to Crystal
The Diamond to Crystal Chest Upgrade is used to transform an already-placed Diamond Chest into a Crystal Chest without displacing the items inside. To use it, simply hold it in your hand and right click the chest you wish to upgrade.

Storage values
Chest: 27 spaces

Double chest: 54 spaces (2 meters long)

Copper chest: 45 spaces

Iron chest: 54 spaces

Silver chest: 72 spaces

Gold chest: 81 spaces

Diamond chest: 108 spaces

Crystal chest: 108 spaces

Trivia

 * Upgrades are slightly more expensive than crafting using the chest, so the only reason you would want to use these is if you have already filled up your chest and you don't want to have to unload the items and reload them again.
 * The Alchemical chest from Equivalent Exchange has 104 spaces and has an EMC value of 8987 compared to the Diamond chest which has an EMC value of 34886.