This drill bit was exactly what I was looking for on this particular project. I had to enlarge the hole in the concrete block a bit. and do it with some precision. This fit was perfect. The downside was that she had a short life. This worked well initially, but soon became difficult due to wear and tear. I didn't think I could finish the job in one fell swoop, but I did my best and did it. One job and the blow is done.