I know, I have worked with Making Armor and Blades in the past. I have a full suit of plate armor made to fit my body. Of course I'm 53 and the armor was made when I was 19.Sharpening steels do exist, but they really are just used to straighten the edge, polish it a little. They barely remove any material at all. "Iron" is not used in any blades, knives in modern metal working. Its brittle and you can not forge it. Only cast it as in a engine block.
There are very high carbon steels used to cut mild steel. But its steel, not cast freaking iron which is useless for a blade.
Not sure what you looked up, but if you are using heat and a hammer to make a edge on a piece of metal you are hitting steel, not iron. There is a difference and its a big one.
Try heating up a chunk of cast iron and smashing it with a big hammer and you will have a splattered mess. Now a true blacksmith as in the craftsmen in Japan who made Samurai swords they could take iron and add carbon, hammer, role quench and all that, real craftsman to be sure but what they end up with is high carbon steel. Not iron. So such thing as "forged iron". Forged steel is a different story and that is what knives and blades are made from.
And when you sharpen it, you use a stone grinding wheel.
I was only referencing the "iron sharpens iron" and that was the results I had found, that in the past, it was used a lot.
I did not understand the reference either, from what little I new of Smithing.