I received this to drill a hole in my foundation wall for a water pipe. He managed to do his job. But the set screw on the pilot drill continued to loosen even after I tightened it with a wrench. After about half an inch you will still want to remove the pilot head. The chisel moved about half an inch in 7 inches of drilling. Two teeth are broken off. For the price I figured I wasn't getting a quality instrument. It's a one time use (maybe two or three) which was fine with me.