Board Thread:Suggestions Forum/@comment-25597877-20141108173409/@comment-27723099-20141109023526

If you want armour to be completely unbreakable, put the "Unbreakable:1" tag on it instead of an unbreaking enchantement.

Example:

/give @p lotr:item.lotr:bodyGondor 1 0 {Unbreakable:1}