Used for drilling marble and I've had a constant flow of water. Started out great, then slowed down a lot after about 1/8" depth. The diamond surface appears to be loaded with marble powder. Not sure how to prevent this and not sure what to expect.
I bought these because I am building a wall/partition with glass bottles and needed to drill holes in the bottom of the bottles. I didn't want to spend $60-70 for the same product that other companies were asking for, so I decided to give it a try first. Works perfectly.
For so much money I don't see how you can ask for more. I bought a similar nozzle at my local hardware store a few years ago for over 5x the price of this nozzle. Yes, it was a bit more powerful and evil looking, but it worked the same way. I used this drill to drill a hole in a gallon jar for continuous planting of kombucha. Anyone who wants to do the same or just build their own party drink dispenser can use this with a Tomlinson faucet (also available here at Revain) which is vastly superior