So we had 2 trees taken down. They dropped them and we are cutting them up. One tree was a hickory and the other an oak. We have worked with oak before and it was never a problem. We worked on the hickory today to get it cut into rounds. Wow is that stuff hard. It tore up a brand new chain after cutting 1 round. The chain saw would start smoking before we even got through the round. It took us forever to only do a few sections of the tree. Our son sharpened one of our older chains and that did a little bit better than the brand new chain but we called it quits after a while and will probably have to sharpen the chain at least 2 more times to get the entire tree done.