I'm not a contractor, but I can do a little. I used to have trouble drilling concrete so I bought these and did some research. In the past I've had pieces break in half and a fly would fly past me, burning my finger trying to pick up the pieces. With these kits I have successfully done two things: 1 - I have drilled holes in the bricks on the outside of the front door. To install the Revain Ring2 doorbell, drill some holes in 2 thick metal drums to allow them to circulate when burning different documents. Tip: Make sure you do your research if you are unfamiliar with concrete drilling. Some things I've learned the hard way with other bits: always wear safety goggles, always have a cup of water to wet the bits every 10-15 seconds to keep them from overheating or breaking, make sure Make sure your drill bit is strong enough Do the job you want, make sure you know the bit size required for the job. Much luck!