They vary from 4" to 12" in dia. This is going to sound stupid because I had my saw with me, but last weekend I just tried the axe on oak. It worked so poorly I got impatient with the thought of cutting, and just carried the logs back to the van in one piece. I have a Silky Katanaboy, and it has extra large teeth, which I think means 5 tpi and a 20" blade. I think someone mentioned that the Bigboy with medium or fine teeth is the ticket for hardwood. However, you'd think mine would be passable. I reeeeally like the price of yours better.