/setunbreakable

Minimum Version: 1.1
(O) Permission: estools.setunbreakable

Player only command

Toggles whether the executor's held item is unbreakable. Unbreakable items don't lose durability and when items are made unbreakable they regain their durability.

In Minecraft 1.11+ this gives the item the unbreakable flag. On versions below 1.11 the enchantment unbreaking 32767 is added to the item.