SALI Wet Diamond Core Drill Bits 4"/102mm Diameter, 15"/380mm Drilling Depth Concrete Core Drill Bit, 1-1/4-7" Thread Core Bit Turbo Laser-Welded Segments with Rebar, Brick, Block, Masonry, Stone

Used to core a 7 inch twice and different concrete walls 15 inches thick.This 4 1/2 inch bit over performed. The curbs took less than 10 mins each and the walls took about 20 mins each. The walls had some big rebar too.Zero issues with quality or performance.After those 4 cores the bit teeth look to be in excellent shape and ready for many more cores. The only real way to even tell it has been used is the nice blue coating is mostly gone.100% would buy again. If I need a different size in the future I will gladly buy this brand.I have seen other reviews, not sure what they are doing but I suspect some aren't using correct drill for this bit. Sure you can use it on an SDS drill, no hammer, but it's not going to drive this bit optimally. You can definitely get the job done with an SDS drill or similar but you really need to get a real core drill if you doing many holes. I paired it with the very affordable Vevor core drill

Did the job, but took a while. I made a jig to position the drill and corebit exactly where I needed the hole. Without a template of some sort the bit would wander and make a mess of the surface. Drill a hole into a piece of 3/4” Plywood the same size as the bit to use as a guide as this bit has no pilot drill.

Very nice. Reasonable price

Had to drill a 1" horizontal hole through a 12" concrete foundation, so I bought the 1" x 15" diamond bit and borrowed a rotary hammer drill with an adapter. I used a garden sprayer clamped to a ladder to spray a constant stream of water onto the bit. This worked well to keep the bit cool and lubed. I also stopped often to dip the bit into a 5-gal bucket of water. The concrete was 100 years old and very hard, so it took me 90 minutes to get through 12 inches, but the bit worked well. I wasn't expecting much for $38, but the bit did its job and shows no noticeable wear. Most important thing is to keep it wet.

Hi. I’m an electrical contractor and have done a fair amount of core drilling using both the expensive Milwaukee core drill rigs and a hand-held version - both with water feed to preserve the bit. And I’ve drilled lots of very hard stone. As such, I learned if a core drill bit is good (has a high percentage of diamond granules around the cutting surface) or if one was cheaply made (with few actual diamond granules). My observation after trying to drill hard stone with this 4-1/4” diameter core drill bit is that this one was very cheaply made and has very few diamonds in it. We exerted great force on the bit (with a good flow of water) and it took several hours to cut 2” deep into the stone at which point the cutting surface was thinned out and laughing at us. I stepped back from the project, purchased a Vevor brand core bit, and it chewed through the rest of this thick stone wall like I would have expected (in less than 10 minutes). I was drawn to this bit because of the length, but please don’t waste your time. Buy some cheap core drill bit extensions if you gotta make a deep hole.

Used it to drill 4 holes through 8" thick granite slabs then used it to frill through 8 inches of concrete+4 inches of granite. Worked like a charm. Not sure how many holes it can do before it wears out but it worked for the five I needed. Seems like it cuts pretty fast too. I used a special masonry drill that provides water to the bit while drilling.

Works good on cement and bluestone didn’t touch granite used with water

I used the 5.5 inch monster diameter to drill a hole in the garage brick wall so I could add a portable AC unit vent for when I was working in the garage woodshop.Tips: We tried drilling from the outside first, but the drill just kept circling off the area we needed the hole. So, we tried from the inside and put it on my rolling workbench as a way to stabilize it. This sucker is heavy, especially with the big hammer drill.Ease of Use: Once we got in on the brick and stabilized well, it went through nicely. However, if did take quite a while. Having the workbench as a support made it possible. It's just so heavy, it would be hard to hold without some type of stand.Connections: I did have to go through 3 different ordering of the core that connects it to the drill. I kept ordering the wrong size. So, pay careful attention to that.It made a nice, clean cut in the brick. It's actually pretty cool.