That being said, this is ring made from pennies. You can smelt the copper coating off leaving you with zinc. Pennies minted after 1983 are all made like this.
You don’t have to have a lathe to do this. You could always hammer the ingot flat and follow the nickel ring instructions. A surprising thing is how lite it is. My wedding ring is the same size weighing 8 grams. This ring weighs in at 3.