Review on Premium Wet Drill Core Bits For Concrete And Hard Masonry - 10Mm Segment Height, 12" Drilling Depth, 5/8"-11 Arbor - Ideal For Wet Drilling Only by Robert Smith

I Needed to drill through 8 inches of a granite stone for a 1 inch pipe. I kept cold water on during the drilling and the bit stayed nice and cool. It took some time ( about 40-45 minutes ) I bought an adapter to use with my drill but the threads were not long enough for the bit ( the Threads don't start at the top so 1 star deduction for that ). Luckily I also have a cordless Milwaukee grinder that fit perfectly. The grinder worked great and I was able to put a lot of pressure on it too without any overheating. I went through 4 batteries ( 5ah each ). I could have used a hammer drill and star bit for MUCH faster results but it would have blown out the rock on the other side. As other have said , you need to start the hole at about a 45 degree angle and then straighten up. The bit has plenty of life left too! Great drill bit.