BOSCH GT100 1/8inch Carbide Tipped Glass

Used bit to drill out an easy-out that broke off inside an aluminum engine block. It worked great. It was the only thing that would drill through that hard of steel. It was a 6mm bolt and did a good job of staying centered in the steel and not wandering into the softer aluminum block. It is a bit slow, took an hour of non-stop drilling. Used water for lubricant.

I bought these to drill holes in my bathroom tile to install a new toilet paper holder and towel bar (our entire bathroom is tiled from floor to about 6 foot high). In order to not chip the tile, I used blue painters tape to mark where the hole should be drilled. This tile drill bit cut a clean hole, no cracks and worked like a hot knife through butter.

Product works well. Good quality.

I’ve fought for dang near 2 weeks on a broken valve cover bolt that I ended up snapping part of an ez out bit in trying to extract it. I just received delivery today and put the bit on my drill and just gave it a shot to see what it does and it ate right through the hard and steel easy out and the broken bolt within less than 30 seconds of me actually drilling. Bosch has gained a lifetime customer with me. This Bit cost me a fraction of what I paid for other bits and methods to remove this bolt. It barely chipped the bit after I used it but I’m so damn happy.

Perfect bit for drilling glass. Worked flawlessly.

If you are using this bit for porcelian tiles, then you batter have a lot of time on your hand. This baby cuts perfect but takes a lot of time because it constantly needs to be cooled. this is not good on a heavy duty construction project with lots of holes. The smaller versions cut better. I have found that using the small holes and gradually increasing the size give the best results but this is a time consuming process. These beat the core drills in that if they were faster; they doo not need to be cleaned out after every hole. Plus there is a very clean hole with no chips at all. If you are impatient stay away the harder you push on these the more quickly they will get dull and can even bend. Slower speeds work best.

I had to drill 3 holes in my ceramic tile fireplace for toggle bolts to fit in to devote my mantel. This type of bit was great as it stayed center at the starting point and powered through all 3 holes. You could feel it getting slower at the third hole but I bet I could have gotten a few more out of it before it was completely dead. Took me about 10 mins per hole, with a cordless 18V drill, and I was taking a few breaks for it to cool and to dip it in water to start again. Overall it was well worth the money and allowed me to wiggle it around the outer rim of the holes to make it a little larger so that the toggle bolt could squeeze in since it’s a tad over 5/8” with the pin. Will buy again if I need to drill into tile.

These are supposed to be glass or tile drill bits but I use these to deburr smaller holes. It does a nice easy job at that! I used a file handle and sounded the stem in to it for grip. Every time I rekey a lock cylinder I use these to debur each pin chamber. It makes the lock run much smoother and last a long time. These have a lot of uses but that's why I got them. They do a nice job

The Bosch GT300 1/4-Inch Glass and Tile Drill Bit is a reliable and well-engineered tool that delivers excellent performance for both professionals and DIY enthusiasts. Designed specifically for drilling through glass, ceramic tile, and similar materials, this bit stands out for its precision, durability, and ease of use. One of the most impressive features is the carbide spear-point tip, which provides smooth and accurate starts with minimal walking. This makes it ideal for delicate surfaces where precision is critical. The tip design also contributes to clean holes with reduced chipping, even on brittle materials. During testing, the GT300 maintained its sharpness and cutting efficiency across multiple uses, outperforming many comparable bits in its class. The bit also handles low to moderate drilling speeds well, which is crucial when working with fragile surfaces like glass or porcelain tile. Another highlight is the build quality. Bosch’s commitment to manufacturing excellence is evident in the consistent performance and longevity of the bit. Whether used in a cordless drill or a drill press, it delivers professional-grade results. In summary, the Bosch GT300 1/4-Inch Glass and Tile Drill Bit is an excellent addition to any toolkit. It offers a perfect balance of precision, durability, and value, making it a go-to choice for anyone needing clean, accurate holes in tile, glass, and ceramics.

Usamos a broca para perfurar porcelanato e foi ótima.

Great product and quality

Lo usé para instalar una barra de seguridad en la ducha del baño. Entró perfectamente y no resbaló en el azulejo.

Shorter than expected based on the pictures - the unpainted part of the shank is only 40mm. The shank is fully cylindrical, with no three-flat design. I used it to drill through tiles. The first hole went well, but the second felt noticeably harder, so I wouldn't expect it to last very long.