Needed these attachments to mount a suspension to my basement ceiling 4 holes of 12mm diameter through aramid concrete.... the key to success was a lot of patience and little pressure on the drill... the drilling attachment showed no signs of wear after long use
I was able to drill the first holes in the concrete. The drills are great and so far they are doing what they promise. However, I have not come across any reinforcement. The quality will probably only become apparent in the long run.