insomniac17 on 25 February 2012
If you keep putting the item in the enchanting table, you'll get randomized levels to choose from. There should eventually be an option for a lv 21 enchant. What you get, however, is completely random. But at higher levels, there's a much better chance of getting higher level rewards.
I've gotten lv 2 Efficiency and lv 1 Unbreaking from levels less than 20. If you enchant another one with that amount of experience, there's a good chance you'll get something much better.
