I am running 2 inch PVC piping between two buildings and the piping had to be routed underground. The first design is a foundation of cinder blocks with poured concrete in the cavities of the blocks. Using an older Ryobi 1 2" impact drill, I punched through the cinder block fairly quickly, but it was clear I'd burn the Ryobi trying to punch through the concrete. And a plain Ryobi cartridge wouldn't last longer than the SDS bit Hold for 30 seconds at a time. For any heavy-duty job, a drill with an SDS chuck is the answer. Rent or buy if you don't have one. I decided to invest in an SDS drill because it's still cheaper, than calling a professional to drill holes and I have plans for the future. So I bought a Bosch Bulldog Extreme SDS Plus. Great tool at a reasonable price. Bosch has done a phenomenal job on concrete with this nozzle. Nonetheless it is It wasn't an easy job. The hole in the second building was completely in concrete. Both holes required a depth of 10". It took me about 2 hours for each hole, but the chisel never stopped working ten. Wrapping tape around the screw and shank held it in place well enough to keep the pilot bit from falling out of the assembly. For faster deep drilling: an SDS bit to knock out the "core" that forms , if you go deeper. It was found that the drill worked faster if I occasionally used the SDS bit to remove the core left by the bit. It was easy to do. It also gave the hole saw some time to cool down between drilling sessions. This beat cost twenty dollars. And the Bosch Bulldog Extreme impact drill can be had for just over $150 and should last the average user a lifetime or two. EDIT 09/2018: Almost worn out. 4 out of 8 carbide cutters came out of the drill. It will still cut, but be slower, and I expect the remaining cutters won't last more than a hole or two. Don't take this update as a negative. I am not changing my five star rating. I've taken this drill bit to extremes: drilling 10 to 12 inches at a time into very hard concrete. drill wear out. With lighter work, this lasts for a very long time. In this case, with very heavy work, the bit lasted a perfectly reasonable amount of time and did the job I needed to do. Would buy it again if I had to do it again.