Any cement workers out there

[NyFirefighter357]

There are two types of very hard concrete the newer high strength that sometimes contains fiberglass "hair" and hard aggregate up to 6,000 psi compaction & then there is very old concrete, that stuff poured 75-100 yrs ago can be just as hard to drill!

[nun2kute]

I've never done this before but you might just chech and make sure you got that drill running forward and not reverse

[6bg6ga]

I always used a Hilti large commercial sized hammer drill that weighed about 50 lbs or so. I used to drill 3/4 or 7/8" holes in concrete to install anchors for equipment racks. I doubt that your seeing any tensioned concrete. I used the commercial Hilti Drill bits available at the commercial/industrial products stores. I once drilled a 1/2" hole thru 30" of concrete in a basement of a 9 story building that was over 100 years old and even with the best bit it took time to get thru it.

[white eagle]

Bricklayer for 20+ years anchored a whole bunch of different items
if your drill aint cutting it check your bit make sure to use a new one
if that does not work get a bigger drill,not drill bit,especially if you are using
home maker drills go to a rental place and get an appropriate drill
there aint no concrete that can't be drilled for anchors