Bit late to this, but I found that when in possession of an excess of iron, the absolutely easiest, no-fight method is to just go insanely overboard. Helve 6 ingots in to three plates, and then just stack the three plates on top of each other. You are left with a perfect block of iron the exact height and width of the 4-way hub, and all you have to do is cut away the excess material.
Granted, this only works if you are willing and able to spend the extra iron to do it. Me and my friend on our server found an absolutely monster spawn of hematite and we quite frankly are in a situation where we are almost never going to run out of the stuff. But, if the Hubs are being really difficult for you to manufacture, then this method of gross excess is perfect.
