VEVOR Diamond Core Drill, 4"/101mm Diameter Core Drill Bit, 9.5"/241mm Concrete Core Drill Bit, 5/8"-11 Thread Core Bit, Dry/Wet Drill Core Bits w/a Blade, Diamond Wet Coring Bit for Concrete Brick

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.

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.

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!

Took bite out of high strength well that consisted of 5000+ psi concrete, masonry brick and cinderblocks. It wasn't anywhere close to fast but it got the job done well. Water helped speed up the process but it was extremely messy... The free cutting disk works great too.

I had to core through a 4” thick concrete floor. This thing really did the job and looks barely worn; like it could do many more. I just stood on a piece of plywood with a 4” hole as a guide to start coring. My son occasionally poured water as we went. It wasn’t long maybe 20 minutes? I used a Milwaukee fuel cordless drill.

I am no expert at coring concrete, but do not buy this unless you have a long pilot bit. Purchased this and a separate sds arbor and this was completely useless without a pilot.

Great product

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

Ha funzionato per 2 volte poi i denti si sono rotti

​J'ai acheté cette couronne VEVOR de 101 mm pour passer une évacuation de hotte et des conduits de ventilation. Pour le prix, je suis bluffé par la performance, c'est terriblement efficace. ​🟢 Les points forts : ​Capacité de coupe impressionnante : Elle traverse le parpaing, la brique et même le béton vibré avec une facilité déconcertante. Les segments diamantés sont de bonne qualité et ne s'usent pas à vue d'œil, même après plusieurs percements. ​Précision du diamètre : Le 101 mm est parfait pour laisser juste assez de jeu pour un tube PVC de 100 mm. La coupe est nette, sans trop d'éclats autour du trou. ​Solidité : Le corps de la couronne est robuste et ne se déforme pas, même quand on sollicite beaucoup la machine sur des murs épais. ​Rapport qualité-prix imbattable : Quand on voit le prix des couronnes de marque professionnelle en magasin de bricolage, ce modèle VEVOR fait le même travail pour une fraction du coût. ​🔴 Les points d'attention (Important) : ​Adaptateur requis : Attention, la couronne est livrée seule. Comme indiqué, elle possède souvent un filetage standard pour carotteuse (1-1/4" UNC). Pour l'utiliser sur un perforateur classique (SDS Plus ou SDS Max), il est indispensable d'acheter un adaptateur séparément. Ne l'oubliez pas dans votre panier ! ​Poids et Puissance : C'est une grosse mèche. Utilisez impérativement un perforateur avec un débrayage de sécurité (embrayage) car si la couronne bloque, le retour de couple est violent. ​🛠️ Verdict : ​C’est l'outil parfait pour les gros travaux de rénovation. Une fois équipée du bon embout, elle transforme un perçage laborieux en une formalité. Je la recommande vivement pour tous ceux qui veulent un résultat pro sans se ruiner.

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