W.D. writes:

Tried the drilling solution w/a 5/8" diameter 13" long masonry drill
and couldn't even punch through the concrete! I was able to get down
about 3-4" after about 15-20 minutes of effort but that was it. I'm
wondering if there is some kind of steel basin that the concrete was
poured into that the drill bit can't penetrate? I paid $15 bucks for a
decent bit so don't think that's the issue.

Use the Tapcon bit I suggested, at least for a pilot. They come in long
lengths.

A 5/8" hole in concrete is huge. The bit will rapidly dull and you can't
exert enough pressure by hand anyway, if there's any granite or quartz
aggregate in there. You have to increase the pressure by starting small
and take it in steps.