Minecraft wiki entry for Crafting_Table, associated text: A crafting table can be used to repair damaged tools, weapons, and armor. When two damaged items of the same material are combined side-by-side in the crafting grid they produce a new item with the sum of the durabilities plus a 5% bonus, with a maximum total of 100% durability for that item. Using this method does not require any experience, but removes any enchantments on either or both items. The only way to retain enchantments is to repair damaged items on an anvil.