VEVOR Core Drill Bit, 4" /101.6 mm Diameter 5/8"-11 Shank Arbor with a Pilot Bit & 4.5" Blade, 9.5" /241.3mm Depth Diamond Dry Coring Bore Tool, Masonry Hole Saw Bits for Hard Concrete Brick and Block

Although I only have an old hammer drill (Hammer off) I drilled it wet. I first hammer-drilled a small hole through the wall. I then ran an evaporative cooler water supply line through the basement window into the inside of the basement. I inserted the water line into the small hole on the inside of the basement and stuffed some foam-rubber insulation around it so that water would come out to the outside of the wall in the center of the coring bit. I then mounted a piece of particle board with a 4-in hole in it to guide the bit. It worked really well! I am 70 years old and I was drilling the hole in a very awkward position but I'm quite happy with the way it turned out. I know that the bit teeth were wearing down, as they are supposed to, because I occasionally saw a sparkle of diamond dust in the water that came out. That coring bit is tough and it has several holes left in it!

I tried this core drill bit (no pilot) in three different drills, just to drill into Aerated Autoclave Concrete block (AAC). AAC is sort of like concrete styrofoam, it's fairly light and cuts easily with even just a handsaw.Myself and two others on my crew could not get this drill bit to work. It was very frustrating, to say the least.We tried coming in at an angle, and using it straight. We tried multiple drills, hammer drills, high torque, low torque, high speed low speed, corded and cordless. No idea why this didn't work other than the drill bit. I've seen people in videos online use this sort of core bit on AAC block, so I can only assume at this point that the problem is with the product.If the seller can tell me why this isn't working ans how to fix it, I will, and I will update my review.

This core drill bit gets the job done and is definitely worth the price. My only complaint is that the bit broke but was still useable. My project was to core out the rusted railing posts for 4 houses, a total 28 holes that were 3-4inches deep. I used the bit for both dry and wet drilling and the bit worked great for the first 10 holes but that was when one of the "teeth" broke off. I do admit that I had my hammer drill on the drill and hammer setting in the hopes to get the job done faster. I am not a professional so I cannot rule out that I was using the bit improperly. Hindsight says the hammering may have created stress fractures near the base of the teeth. Despite one tooth breaking off, I continued the job but this time only using the drill setting until hole 18 where another tooth broke off. The earlier hammering was definitely hard on the bit but I continued to use it with only 2 teeth remaining and it survived until the end of the project. Overall, I am happy with the product because of its great price and how well it endured in the hands of a newbie DIYer.

I recently drilled 2 holes through a block wall for venting purposes. The first one... took me an hour and a half... it was solid poured and had 4 pieces of 5/8 rear in it. While it did take a minute to get through... it persevered. The next day I drilled through a different area and it was regular block... ate it up easily. This bit is still in good condition and I will be able to cut at least a few more holes with it.

I’m happy with the purchase because I needed to put 1 hole in 10” concrete. Worked satisfactorily. As others have noted, the pilot bit is total garbage (allows the core bit to wobble uncontrollably). I used other bits to drill a pilot hole and a piece of 2” foam with a 4 1/4” hole as a guide to get the core hole started. Once the hole was started, worked well. It fit my SDS plus hilti. Other bits I’d considered would’ve required me to rent a SDS Max drill which would’ve cost more than this bit. If you’re looking to core just a few holes, this works well.

This bit it terrible and screwed up my wall. The cent guid bit is weak and allows the core bit to wobble and crawl all over the place. If I could make them pay for the damage this thing did to my wall I would. It was flat out trash in my experience and completely unusable. I would give zero stars if possible.

I used the 4" dia version to cut a hole into my driveway to run drainage with an angle grinder. This core drill worked great, I used a piece of plywood with a 4"hole to guide my start cut. I can see how using this core drill horizontally would be much trickier, it's a heavy bit. I didn't break any teeth, and the bit held up well. I was in a low spot so it was easy to keep water on the bit. I was impressed with the results.A few observations. I bought the version without a pilot bit. This core drill is so long that the narrow dia. pilot bit would probably be a joke. If I had to use this bit dry I would take lots of breaks and put it in front of a fan in between.

Dry cored through 3 5/8 brick just fine in about 3 minutes. The pilot was way too flimsy to be effective. Had to angle the bit and start it on edge. Barely took the paint off the bit.For the price, can't beat it. Don't know about the longevity of the bit since I only needed one hole to move a dryer vent.

Just received the core bit I ordered and it came used. Still has dust in it and rusted. Not impressed

Was a little difficult to get started without the center bit. Once it started I was able to finish the job.

Très bien et Très simple d'utilisation

30 cm de beton..( a sec ) 1h30 honnetement je n'y croyais pas

Je voulais faire trois trous au mur en béton, à la première utilisation sa été très dur j’ai quand même réussi à percer, par contre c’était terminé le deuxième trou impossible 😖