I only read the first and last page, so if anyone already said this sorry. If you are cutting logs on the ground you are hitting the dirt. All it takes is an inch long cut in the dirt and it's like sticking your best stake knife on a 12,000 RPM grinder. A few years ago a guy came on here and said he kept buying bad chains, they were dull out of the box. Some one told him to post a pic of where he was cutting, and giving instructions on how to file the saw. His local tree company was dumping logs on his concrete drive way. You could see the marks on the concrete where the tip broke through on every cut. When we called him on it, he said, "Oh, that little bit doesn't hurt". Yes it does, especially if you are seeing sparks fly.