Is iron treated the same as gold and silver when exchanging one ton of 3-gauge iron for one ton of 4-gauge iron approximately one year later?

Scholars have differed regarding the inclusion of iron among ribawi (usurious) commodities. The Hanafis, and one narration from the Hanbalis, hold that it is included due to the commonality of weight, and they stipulated equality and immediate possession (qabd) when selling iron for iron. Whereas the others held that usury does not apply to it, and that the 'illah (effective cause) in gold and silver is their monetary value, which is the preponderant view. Therefore, usury does not apply to the sale of iron for iron, and disparity (tafadul) and lack of immediate possession are permissible. Selling a ton of iron for a ton of iron is not problematic, due to the equality of quantity regardless of the difference in quality, especially since the preponderant view is that usury does not apply to it.