Overall a pretty good drill bit. I needed to drill five - 2 inch holes through a 5 inch thick reinforced concrete floor. After starting the pilot hole, it was tough to get the large bit started due to the size. I found starting more at a slight angle, then gradually moving to a straight up angle made it easier. It is not an easy hole to drill, but this drill bit works well. The only negative is the set screws for these pilot drill bits will vibrate loose causing the main bit to really wobble badly. I had to retightened the bit often. And.. Definitely use water. Much faster, cleaner, and no dust. Well worth the money compared to hiring others or renting equipment.