Two problems 1. The 2" drill bit bent when drilling to a depth of about 1/2" in 1" deep artificial stone. It was a wet cut and the stress was very light. About 1/2 the drill began to oscillate and the drill surface and shank became flexed. I was able to finish 1 inch deep but the drill got stuck 2 times because of wobble. I am returning the drill set.2. The top end for the mounting pad is just round. As the drill rocked and vibrated, the chrome coating would come loose and begin to slip. I have to manually remove a stuck masonry bit 2 times when drilling 2" in diameter and 1" deep. I recommend a hex bit.