What is used to make iron ore?

Answer 1

iron bars are used to make anything that you can make at the anvil with the hammer, it will give you a list of stuff to build different stuff requires different amounts of bars. when you make iron bars they only need one iron ore, but there is a 50-50 chance of successfully making an iron bar

Answer 2

iron ore itself makes the iron bar but unless you have the superheat item spell you have a 50% chance of converting ore to bar now though after an update some time ago once u get i think lvl 45 which then it becomes 80%