Manufacturer's Note: If you're having trouble cutting a wall, your tool isn't strong enough, you're right. I tried a 1/2" hammer drill and it wasn't strong enough. Cuts about 1/4" in about 1-2 hours as others have stated. I went to a tool rental shop and asked what size tool I needed, to cut a 5" hole and they pulled out this massive tool designed primarily for cutting 5" holes in brick/stone/concrete. Let's just say the tool helped a lot. It always has still slow but I got through the rest of the brick in about 30-45 minutes (only 6"). I've compared it, I've seen this production sell and the tips aren't as sharp as the rental company ones. But this 5 inch hole saw cost hundreds of dollars, so $85 for a set is fine with me.