No, iron plate was used as my estimation of what sort of armour the axe could bypass, or rather, Sigurds estimation. I left in plenty of info on what it could do, break bones, perforate armour, and easily destroy flesh. Not necessarily all these things at once, but a direct hit from an axe in these circumstances would be pretty bad, and comparable to the exact scenario in which they were used historically where they were known to absolutely fuck up the front line of a charging enemy, including smashing straight through hide and wood shields.