Rakers don't like nails much. Nor do the cutters. I knew that an old tree stand once stood in the tree, so I was actively looking for nails. I avoided all that were on the surface, but found some that must have been nailed in to the tree 20 years ago. They were 6 inches into the tree and made a mess of the blade. That was the last section of the tree I was cutting. It was at the base, and the center was rotted to some extent, so I left it there. There were likely 40 good splits that could have been harvested from the outer rings, but I called it once the nails were hidden like that.