Dry Diamond Drill Bit Set,BGTEC 5pcs 1/4" 6mm Hole Saw for Granite,Marble,Masonry, Concrete, Tile/Ceramic, Glass, Hard Plastic,Vacuum Brazed Diamond Core Drill Bit Kit

I was stopped by rocks in concrete that refused to submit to carbide masonry bits (Bosch and Dewalt, both). The rocks rounded off cold chisels and just wouldn’t submit. I ordered these in hope of getting through and sure enough, made it past whatever they were made of. Was not rebar.I made the mistake of trying to drill with water in the holes. The bits stayed cool but that meant the wax plugs up the middle didn’t melt and had to be ground away by the concrete core that builds up the middle. Not a huge deal, just would have been slightly faster with less junk in the water if I’d let them heat up.I did bend one bit using a Milwaukee M12 cordless hammer drill. Don’t use the hammer function with these. Otherwise all went well and they did exactly what I wanted them to do. It was not a hot knife through butter like one of the other reviewers stated, but they did get through some serious rocks that brand name carbide bits refused to drill.

Working on a big project of 252 bathrooms. These have saved a lot of money and have been just as durable as the others from the big box stores at $18 each. The get clogged and you have to clean them out, if not trash it and grab another. It’s only $3 a bit compared to the 18 and still getting 12-25 holes per bit.

They work great once you have burned up 1 or 2 in the learning process. They are pretty much one hole per use then discard.They drill porcelain tile with ease but throw away after one use and that’s completely ok for the price and getting the job done.I have bought these several times

I purchased them to drill holes in glass tiles that I used for my BBQ island and was skeptical of the 'wax' filled centers - all other bits rely on water to be cooled, but since I'm working on upright cement board project that I don't want to get wet I hesitate using water - THIS BITS are amazing - as soon as I started using them I could see the 'wax' flowing the cutting out and one bit lasted the drilling of 6 holes I needed to attached the vents to the island - the cutting surface stays strong, did not overheat, and must importantly bit not crack the glass tiles at all specially since the holes were positioned close to the edge of several tiles! Amazin as I said before! Very impressed!

I was a bit skeptical about it working dry (because of the wax center) but it cleanly drilled 6 holes in porcelain tile for a shower grab rail with amazing speed and ease. My only regret is that I bought 6, and needed only one, so now I have several I may never use!

I recently installed 3/4" porcelain pavers on my deck. After- we decided to add a pergola. I burned up 1 each of name brand diamond bits, then tried these on a whim. They are truly incredible. Even though I used water, the bits still got hot enough for the wax to melt and lubricate. It was like drilling a hole in wood. As a bonus...the whole looks like it was cut with a waterjet or laser, not rough at all. I couldn't recommend more. No need to keep looking....these are what you need.

Drilled only four holes into porcelain tile. One of the bits literally bent. One of the holes led to a broken porcelain tile. Fortunately I bought extra, knowing that cutting porcelain is tough, but I was disappointed that it was this unreliable. I'd say unless you are going to be able to hide these holes if something goes wrong, porcelain might be too tough for these bits. The price was I think excellent for the quantity and comparable prices at other stores. Our local stores didn't have any, so we had to look online. Be modest in your expectations.

These worked great. Remember to start at speed on a 45 degree angle. Use a bar of soap to lubricate during drilling, a trick from my stone installer. I probably got 4-6 holes each in 6mm porcelain slabs.