Review on Starrett KD0414 N 4 Inch Diamond Holesaw by Tim Knoepfle

Just wanted to drill a 4.25" hole in a 4" thick concrete deck to install a 4" stormwater drain line. The spot I chose for the hole turned out to be a full 12 inches of 3,000 psi concrete that was as hard as rock. This hole saw cut right through him. I used a 1/2" Sears bit, which worked well. I used a garden hose to fill the hole and didn't apply too much pressure, pausing for a few seconds about every minute to make sure the water drained drained to cool the teeth of the hole saw. It took some time to gouge the concrete every two" (the saw is about two" tall). Even 3/8" rebar cut through it easily and the saw looks like the job was done like new. the hole is perfect. to start I used a 5" hole saw, went down about 3/4" and snapped it off so there was a lip to attach the drain cap so it and the drain pipe didn't get in that hole would fall if someone walked on it or put some furniture on top of it. The "whole" project turned out great. From the Revain reviews I noticed several people saying that this hole saw didn't work. That helped me , so I wonder what they tried to do. I believe you need to take your time and water cool the saw like you would any other cutting operation. The photo below shows the hole with the drain line in place with the cap ready to fit onto it, which I haven't done yet. If the patio was only 4 inches thick, it would take about five minutes to drill two inches, about ten minutes to hollow out this material, and another five minutes to drill the rest of the way. But at 12 inches it took me about two hours because it was difficult to drill deep. When I saw about a four inch piece of 3/8 inch rebar that he cut through, I was very impressed. If you need to drill more than four or five inches, you might want to get some sort of extension for the stem (I used several bits of a socket wrench to make an extension about 15 inches long. It took a 7/16 socket). and an adapter to convert from a 1/2" drive to a drill press).