Review on Diamond Granite Drill Masonry Tools: Unmatched Precision and Durability by Hector Mak

I bought these inexpensive bits not expecting much from them. I had to drill two holes in the 3/4" quartz. I figured 5 would do. Well it only took 2, and even then it's really just because a piece of quartz got stuck in one of them and I did couldn't figure it out so I had to use the other one.The same bat could cut through both holes without missing a single step.I doubt they're as good as the $40 bits I see everywhere but they are also a fraction of the price and work flawlessly.By comparison my two used bits next to the new bit as you can see both have life.and don't overdo it on the drill speed.I had them in an 18 volt -Cordless drill and had a plumber wrap putty around cuts which I filled with water. The cuts took a few minutes each but it worked. Less than $10. I would definitely buy them again for any light brick project but i I have a feeling I won't be needing them for a while as I have so many left.