Blue Granite โ now thatโs a name that instills confidence. Boschย was going for the manly persona when it came up with that one. Of course, what elseย should we expect from a German company? Carbide hammer drill bits are madeย for one thing: fast impact drilling in concrete, stone, or masonry. Theย Bosch Blue Granite drill bitsย useย a high-temperature brazing process to keep the carbide cutting edge fromย breaking out during deep drilling when bits tend to get very hot. The bits comeย in various lengths up to 12โณ (usable lengths up to 10โณ).
Testing the Bosch Blue Granite Bits
In our use of the Bosch Blue Granite drill bits, we fitย a 3/16โณ Blueย Granite bit intoย our DeWalt DCD985 hammer drill. We then let โer rip into some concreteย block. The goal was to secure a piece of pressure-treated lumber to the wallย courtesy of four Tapcon anchors. The hammer drill easily drove the Bosch bitย into the concrete. Since this job involved plumbing leak repair, we encountered some wetness. That stuck to the bit like paste.ย
Normally, the dust would be easily extracted by pulling out the bit andย plunging it back into the hole. In our case, we had to remove the paste manually using our fingers. Itโs not a show-stopper, and we certainly donโt think any otherย bit would have done better.
Tech Note: Brazing joins two or more close-fitting parts by heating a filler metal orย alloy to a melting temperature above 800ย degrees F (427ย degrees C). Atย its liquid temperature, the molten filler metal and flux bonds with a thinย layer of the base metal, and cools to form a strong, sealed joint.
Using the Bosch HCGB700T Bit Kit Over Time
We found that the carbide tip of theย Blue Granite bit stayed sharp and well-honed. That stayed true even after drilling through whatย amounted to 6 inches worth of concrete block. We also found that the bit seemedย to really tolerate high-speed drilling with the hammer drill function engaged. Thatโs something you wonโt have much luck with when using a non-carbide-tipped blade.
Overall, the Bosch Blue Granite drill bits from Bosch is a goodย bit for masonry drilling and we highly recommend it. There are other choices,ย but these bits are actually a great value and not priced at a premium. You canย also find them nearly everywhere and they come in convenient kits so you alwaysย have the size you need.
