Ive drill through marine concrete on a house boat with a special bit before, csrbide tip but the spiral thread is slightly different to normal masonry bits.
More of a grinder than a drill to be honest
Nice bits of kit
We had a large cast concrete sewer pipe on a job, and needed 110mm hole for a new drain to feed it, a very very expensive carbide cutter was purchased for the job, then before I could pick it up from the office a certain sly fat git liberated it for a cash job on some body else's site
I was pissed off as I had ordered it specially, plus hired in the special drill with clutch
Oh and the office was closed that weekend so I could work without the sewer being live
Ended up putting a curved sheet of timber inside the mahoosive vertical pipe, then drilling very very slowly with a new 5.5 mm sds bit no hammer though
Needledrilling it's called
I dragged it out all day. Then returned the next day to clear up dress the edges and set the pipe in with cement
There was a lot of complaining about my hours, and that I could have waited till the correct tool was returned
Tuesday morning g sewers working nice, new joint set and working
Fat arse turns up and tries to slide the cordless sds drill and bit into my workshop for collection
Told him to feck right off, he has signed for it he returns it
Just as well, he had dropped a brand spanker new hire drill, a grands worth in the poo poo
Buggered up, also the battery had come away from the body and gone down the drain, along with the expensive but which clicked out as he put his hand in the poo desperately trying to retrieve it
Hire company took one look a few pictures, and skipped it
Best bit was the mong had cracked the sewer pipe, 3 days work to dig it out and replace, plus check for blockages
Oh and they didn't pay him
I got my overtime though