4" Dry Diamond Core Drill Bits for Brick and Block with 1/2" Shank Pilot Bit Adapter, 9.5" Drilling Depth, 5/8"-11 Arbor

Yes, the core drill held up and drilled several holes in concrete blocks.

This 4-1/4 inch diamond bit cut through brick like butter. Very quality tool, works as designed. This investment save me several hundred on the installation of my dryer duct. Shipping was fast and great packing. I’m not a plumber, but this tool made the job very easy.

It made me easy work! Great tool!

Had to bore through the foundation of a new home to install a replacement water main. High aggregate concrete block, with plenty of excess mortar along the way. This core bit did the trick with a traditional electric hand drill. Took a while but it left a smooth hole and minimized damage to the block wall (which is why I elected to use a core drill rather than just blasting through with a hammer drill). Worked like a charm.

This core bit really works as advertised and beyond. I had to core out an external wall for a mini-split install. The wall is drywall, insulation and 8” of cinder block; not all the cells in these type of walls are concrete filled, but I won the jackpot and hit concrete and a 5/8” rebar. The concrete was easy, the rebar took a little longer, but it got thru. No hammer impact, just slow drilling with light pressure on the drill.The only downside is the guide bit; the set screw comes out due to the vibration, no matter how tight it is. My suggestion is to drill the pilot hole just with the guide bit, then use the bit and core to score the hole. Once it gets going, you can do without the guide bit.

Worked great for cutting out 4inch hole, but should've gone up one size larger to make it easier to fit 4inch pipe. Also will need a strong hammer drill to turn this without burning out.

Set this all up, seemed to be great.All went bad within 30 seconds of use.First, the primary bit would not stay tight in its arbor no matter what I triedSecond, because the primary bit was loose, the block cutting would bind up causing either the drill to stop or worse kick and snap causing wrist and hand injury.Does not at all live up to standards.I ended up using regular masonry bits and the out line from this tool to drill multiple holes and complete the task.Sending this very dangerous item back as it did not at all perform properly.Be careful

Like many other commentors I was adding an bathroom exhaust to the outside. A long deep coring tool looked really promising and at this price point I took the plunge. Initially I purchased the Bosch coring bit but that sucker was expensive for just a 4' deep hole saw. And to top it all off they didn't have a Bosch bit adapter in stock. So I put it on order for the next day or so. When I saw this on Amazon I was thinking hey this is a great cost effective solution I can return the Bosch. The bit started out great by cutimgt through the brick like butter however cutting through the wood was a major exhaustive battle for me. The night fell. I even tried to finsh the cut with my 4' wood hole saw and that is when I discovered that this hole saw is not really coring a standard 4' hole. As a result I could not get my wood saw past the brick. Finally on the next day picked up the Bosch adapter and decided to sacrifice the Bosch to finish the job. I was able to open up the hole to a proper 4 3/8 which allows proper fitment. Because I used that the deep coring bit first it made finishing with the Bosch a breeze. But I paid a high price in the end. I am not certain I would have been any better off if I had just started out with the Bosch because it was much to shallow too core through about 9 inches of material