I'm not 100% sure what you mean by iron-bound shield, but if you're referring to the Iron Buckler then a Silver Shield is a major upgrade. The lowest end Silver shield is also better than the highest end Banded shield.

Can you block a golem attack though, that's the question. To which the answer is yes, but I do think some damage will still bleed through.

This is steering you pretty far away from your original question, but stone golems are not fond of pickaxes. Something to consider perhaps :)