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

This hole saw did my job with ease. Boring though brick is slow and time consuming. But this tool was up to the task. Good clean accurate cut. I used a 500 rpm 1/2” rotary drill. This tool does not require a hammer drill. Good value for the money.

I only needed to drill one hole in the concrete. This worked perfect. I decided to keep the area wet to cool the bit and keep down the dust. It worked just as expected. It took about 10 minutes to drill through 4" concrete floor. I took short breaks in this time to pour water on it. I do recommend using at least a 1/2" drill with good power. Also, if you use water remember to use a GFCI outlet or cord.

When I opened the box, there is a sticker saying this isn't for concrete. But I hooked it up to my rotary hammer drill and drilled a curb hole for a French drain and this thing worked like a charm. Only problem is it was heavy to my drill bit connection for my SDS plus adapter kept breaking. Took a couple days just because of the adapter, but this drill bit delivered and didn't break.

Great 4inch hole saw. Very heavy duty and plenty long. Installed a new bathroom fan in a basement bathroom out an exterior brick wall. Like others have mentioned to get started, the pilot bit is not enough. I cut a 4inch hole in a piece of plywood with a jigsaw to keep the bit from sliding on the brick. I placed the plywood on the ground with my feet wedged against it to hold it in place. After the pilot bit was in 1/4 inch, I removed the bit. I’m not sure the pilot bit was even necessary. After removing the pilot bit the drilling went pretty smoothly. I was using a Dewalt corded 1/2 drill DWD210G. The drill had plenty of power and was through the 4 inch brick in less than 10 minutes. I cut this dry, lots of red brick dust so wear a respirator and ear muffs and put down some cardboard to catch the dust to make cleanup easy. The bit also cut through the wood 2x4 and the plywood from the floor joist. Very clean hole highly recommended. Bought a vent from HD “no pest vent” which fit great.I will never use my sds drill bits to chip out a bigger hole again,this was so much cleaner and quicker. I have previously chipped out an outside spigot and radon fan pipe and that was not fun.

I had to core drill seven holes in brick wall for electrical boxes, wife went overboard with her backyard light design but it is what it is. The brick veneer is about 4” thick, very hard stuff. I’ve got 4 1/4” core drill bit, the main reason it was on sale and much cheaper than 4” diameter one. Here is what I found.1. You absolutely have to drill the guide hole first separately, the included center bit will not do anything unless you remove it, drill the guide hole in hummer mode, then reinstall it back for core drilling which is rotary mode only.2. You really don’t want to use cordless drills, whatever strong it may be, even my 7A corded one barely had enough power for 4 1/4”. It started smoking at the end, so I’ve pulled 13A Milwaukee SuperHog which was perfect for the task on low mode.3. The bit lasted me through 7 brick holes, but the 7th one was much slower, I’d say the 8th one will be the end of its life.4. The included M8 nut to hold the center guide drill bit is garbage, the hex wrench doesn’t have enough torque to make it tight and is awkward to use. I’ve lost it on my 3rd hole and switched to M8 bolt which was much better.All and all the bit did what it is supposed to do, for the money I’ve got everything I wanted. Except the hex nut design I have no complaints.

The cut quality was great, it fit my cordless drill. When drilling the hole in brick, be patient when using it and keep spraying water on it. The cost of it was great. Used it to drill holes in wood and that worked well.

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

Went through 12 inches of hard poured cement with large rocks in it. Took a few hours to avoid burning up the drill (A Bosch Bulldog). Takes a fairly powerful drill as mine was about limit for a 4 inches hole.I used water while drilling. And took out the core bit from the hole every couple of minute to dunk in it in a 5 gallon water bucket.I have no idea how many holes I'll be able to drill with it but it still seems in good shape.

The center drill I found also came loose or was wobbly, once I started to core it was working good but then got stuck halfway and half the teeth Broke off.Used for 5 minutes.