Answer:
The easiest way to make a ring may well be to take a square piece of iron drill a hole the same size as the ring size need. then using a hacksaw cut the corners off the square making it eight sided. Then take a flat file using blackboard chalk as a lubricant file off the excess material until it is round. You will also need a round file to round the edges of the hole so it is not so sharp as to cut your finger.