I have used wrought iron pot hooks, and they are twisted, round, or square in thickness. The reason for this is that it takes the blacksmith less time to shape. They usually started with a long rod and shaped it, sometimes flattening it in the process. Some blacksmith got square raw iron to start with, and twisted it to make lovely designs in the metal - These appear to be flat/ovular stock.
However! Pot hooks these are not. I grew up in a house built in the 1700's and these are window latches or storm shutter latches that have had their eye-ends stretched open. This (now open end which was once a loop) is the one where it was fastened onto it's permanent side. The curved but not closed end then slides around a peg or knob to keep the window or shutter closed.?