Minecraft wiki entry for Armor_farming, associated text: An anvil is crafted using three iron blocks and 4 iron totaling up to exactly 31 iron. In order to get this amount of iron you can mine for iron using a stone pickaxe or above, or you can make an iron farm. It is recommended to mine 31 iron ore, then smelt it in a furnace, or a blast furnace. Once you have done this, in a crafting table place one iron in each slot of the table to make an iron block. Repeat this two more times. Then in the crafting table place the three iron blocks on the top three slots, on iron in the middle slot, and the three remaining iron in the bottom three slots. Then you can craft the Anvil. You may have to do this multiple times, just in case the anvil breaks from a lot of combining enchanted books and armor.