QEP 1-3/8" (35 mm) Xtreme Diamond Hole Saw with Water Delivery System

This was the first time I had done anything like this and was a bit intimidated by the prospect of cutting hole in 1.5" of pristine granite countertop, which was not my own. But there was little reason to be I found out.THE GOOD:It took less than 10 minutes since I took it easy and checked the hole often. Probably will be half that the next time around.All I had to do was keep the drill vertical and make sure it wasn't going off at an angle which the guides helped with initially.It did almost all the work, I put only a little bit of pressure. The weight of the drill and whatever pressure the weight of my hands and arms coming in at a 15 degree angle from horizontal. Which really was not much. It is an abrasive cutter so it just wears away the material that it is rubbing against.Clean cut all the way through except for a 1mm thick piece at the end on about 1/8 of the circle that was about a couple of mm beyond the hole . But not a big deal at all. The core fell right out.Couldn't have been easier.THE BAD:The adhesive was not great and kept coming away from the counter top. I had cleaned the countertop with alcohol and made sure the surface was even. But it was polished, might have been difficult to stick to. It did seem like it stuck pretty well at the beginning, but the water mixed with granite grit seemed to infiltrate the area in about 30 seconds. Between that and the vibration of the drill I had water leaking out the sides fairly soon. No problem, I had another person lightly hold it down and that took care of it.OVERALL:I would say this is an easy project if you take your time and are careful to keep the drill vertical/straight down. Also, flush out the water once it starts getting opaque, seemed to work better with clean water but maybe that was just my perception.Keep the drill at a low RPM, try it and see what you find works. In my case I put my electric hammer drill in the drill setting (no hammering!), low speed and I had the trigger about 20% in. Tool low and I kept feeling the drill wobble. To fast and it seemed like it was just spinning without doing anything useful. For me it was just fast enough that I could barely feel or hear it wobble. YMMV. Part of the reason for the wobble might have been that my hole was not perfectly straight and as the hole progressed I hole saw was touching the cut surfaces a little bit.Can't complain, it worked out really well. Good luck with your projects!

Great value, this thing cut through my stone counter and stone sink very smoothly. I was worried about this DIY project bc I didn’t want to destroy an expensive kitchen. I also didn’t want to pay someone $100+ to come and drill a hole. I almost took off one star bc the water did leak from the plastic cup/guide but compared to the mess dust makes this thing is genius. If you need to install a filter faucet, disposal switch etc just buy this thing and go for it !I used a 18V makita power drill. Start on “1” low rpm in drill mode (not hammer drill mode). Used a slight angle, then straighten out. I needed to apply a bit of pressure to the drill but took my time and let the bit do it’s thing.

This drill bit helped me make an existing hole bigger. I was quoted $400 by the countertop installer and $100 by a handyman. I have never drilled quartz before and the whole process took about 30 mins with a cheap cordless drill.The blue guide is very helpful to get things started but once the drill bit is few millimeters into the quartz, the guide is largely unnecessary (but reassuring).I gave it four stars because1) the guide came unglued midway through the procedure2) I am skeptical if the drill bit can be used again. It looked worn out after the task was done.

I added a RO water filter under the sink and needed a second hole in our quartz counter. This worked perfectly. Just followed directions and it was done in a couple of minutes.

I wanted to install a cup riser in my bar sink and needed to drill a hole into my quartz countertop. I bought this QEP diamond hole saw with the jig and adhesive, which was super easy to use. Make sure the countertop is CLEAN before applying the adhesive otherwise it'll leak and fall off.After marking and sticking the jig onto the sink I added some water to keep the diamond blade cool when cutting. It took about 3 minutes for me to cut through the quartz countertop and was left with a nice clean cut! I added a bucket underneath the hole to catch the chunk of coutnertop and all the water once the hole was cut through. Saved a lot of clean up time! Let the drill do the work and be patient!I like how the kit came with multiple adhesive stickers for multiple projects. I can definitely use this for future projects!Highly recommended!

This bit and the system worked very well in a granite countertop for the one hole I needed. Don’t know how it will perform the next time I might need it, but even if I only use it one time it was quite inexpensive compared to hiring someone else to do it.P.S. Need to use a quality high speed drill. Started of with a cheap low RPM tool and made no progress.

I'm using it to open holes in marble tiles and it works fine. It comes with a few pieces of adhesive (I believe 5). I'm not sure if they sell them separately.

Worked perfectly