I am a pretty serious DIY person, but don't have a ton of experience with diamond tools. I needed to bore a 24" hold through a granite boulder. I purchased the EDiamond tools higher-end 1.5" boring bit, 12" extension, adapter and water adapter. Worked like a charm, and can see no discernible wear on the diamond blade. Follow the RPM recommendations on their website and don't put a lot of pressure on. Let the blade do the work. My big HD drills were too slow RPM-wise, so I ended up using a cordless Ridgid drill on high speed. Went through three batteries but it worked great. There is no pilot so you need to either use some form of Guide to get it started without the bit walking. Or do what I did. I started with a regular Home-Depot 1.5" tile hole saw so there was an 1/8" deep circle for the Big EDiamond bit to get started.