[aylad]

What I didn't understand is when you take a bar of iron - what's that weigh? About 2 kg? And then you shape it on an anvil, some of the things you turn it into are heavier than the bar. I think the hat skeletons are that way. You're not adding anything to the bar, you're just using one bar, but it comes out heavier.

I can understand the item being lighter, because maybe some iron is wasted in the forge, but heavier? No way.