"I used the SDS adapter with the 52mm core bit & it did the job. Unfortunately it became difficult to remove from the chuck. This turned out to be because it had slightly twisted in working. I continued to use it & with the 200mm extension & it completed the job. Obviously the steel is not hardened enough . I did not abuse the tool but I guess the required torque did the damage at some point. No downward load was placed on the drill but it can snatch the odd time ?"