I got a bit of yellow pine lumber that came out of the bottom of a grain bin(it was holding up the drying floor, but I think was originally part of some house truss) and was processing it the other day. Pulled out a ton and a half of nail/screws. I ended up running one nail through my jointer so I had to flip a few cutters on my spiral head. I then proceeded to run everything through the planer, and as I was catching a board on the outfeed I hear a noise and looked at the board and there were close to 10 bright shinny spots! How could I miss that many nails/screws? Oh and I had just put in new knives..... so I pulled the board aside and ran the rest through. I went back to work on the problem board and looked a little closer, and started digging only to find out that someone had peppered that board with a shotgun! It looked like #5 shot or so. I'm guessing some coon or other varmint was under there and the PO decided to eradicate it. Anyways although it was probably hard on the blades, at least it didn't nick them, as everything is still coming out flat.