DUNCHATY Diamond Drill Bit, 10 pcs Glass Diamond Hole Saw Set Drill Bits Extractor Remover Tools for Ceramics, Porcelain, Ceramic Tile 6mm - 30mm

Cost effective. Work great. Drills though tile well.

Originally, I didn't have a lot of expectation on this because of the low price. But after drilling several holes on porcelain tiles (totally 16 holes), I am convinced. I have some Milwaukee hole saws which I paid 30x - 40x times more. Believe it or not, this Made in China hole saw kit even drilled smoother and faster than Milwaukee, unbelievable. Perhaps, it may not last as long, but if you are occasional DIY home improvement guys, who cares. This is definitely recommended since you don't drill tiles every single day. Notice in the photo, my 1/4 Milwaukee bit got rust on it after 1st use while this kit has no rust at all. Absolutely 5 stars.

These glass drilling bits got the job done in no time at all! Used them to drill holes in the bottom of glass blocks so students can light up their stained glass project when they finish. Excellent selection of diameters and well made!

I tested some bits opening two holes in a 5 mm glass. The one inch bit worked very nice and smooth opening the hole in the glass very easily. The one and half inches bit was able to open the hole but it looks like the bit is not well centered as you can see some tilting when the bit moves and it was slightly harder to open the hole in the glass which is not a perfect circle like the one obtained with the one inch.

Worked well for cutting holes in ceramic tiles, a little awkward getting them to stop skating out of place but having an adjustable speed drill helped and a squirter water bottle to keep the bits cool while cutting, once you cut through the glaze it's real easy. Very pleased with them.