I had to drill a hole for a street lamp. The hole should be cut into a standard brick and mortar lamp about 4 feet tall. The chisel worked well at first, then it started to fail. I used a 1/2 HP impact drill that seemed to work fine, but not very well. At some point the drill got stuck in the drill hole and could not be removed. It collapsed in the hole, leaving me toothless and about a foot from my target. I don't know if that was a beat or my usage because I've never tried anything like this before.