Dremel 664DR Diamond Drill FlipBit

Ok I read the instructions. Had water on the ready! Went slow! Did not force the bit! And oh it went through beautifully but the instant it went throughIt (the bit) broke!!!! It’s easy to use. Cuts great but it’s a waste of money to pay that much for one bit to break that easy!!!I just wanted to revise my review due to the kindness and support I received from The Robert Bosch Tool Corporation. I called and explained what happened and Andy M was very helpful and understanding concerning my problem. He promptly addressed the situation and mailed me out not only one replacement but 2. Now that’s what I call AWESOME Customer support. Something more companies should take advice from. Thank you Andy M !!! You’re the BEST!

Unfortunately I dropped my dremel one night and snapped tip off , so I needed another. These aren't always in-stock in big box store. This is name brand and the quality you would expect when you use it properly just don't drop it like I did. LOL. You can see in second picture what I use these for. I went ahead and bought 2 so I wouldn't be without. I really do like that I have a thin more precision side and a thicker side that cuts through faster

Seems good. It works both ways.

I do not recommend for drilling agate. Bit will dull quickly or break even under water. Never use dry for drilling stone. Works well for materials of 7 or less on mohs hardness scale.

Looove this bit. Perfect for drilling seaglass! I just wish the bit would last longer as each end only gets through 10 pieces at most.

Perfect diamond drill bit for my glass pieces.

Bit worked exactly as planned. Having two different size drills on one bit is great. Did drilling in a water bath. Bit maintained its sharpness, last hole drilled was as clean as first hole.

I have had two of these, and tried using them on an intank aquarium air filter that I was building out of an only glass vase. The bit worked great for a little bit, but quickly wore out. I used this in both a drill press and in a hand drill with both water and WD40 as a lubricant. Again, the bit worked well for a short amount of time, but the bit wears out quickly. The only reason I bought the second bit was because I was hoping that it was just an issue with the first bit, and I wanted consistency with the holes I was drilling. Unfortunately it wasn't just the first bit, as the second bit wore out quickly as well.