Decent piece for the price. My problem is with a smooth round bar. Your working with the 2" drill causes a lot of friction/resistance and I could not tighten the chuck enough to keep the drill's shank from slipping (key type chuck). I have drilled a deep well. to 6x6, so I had to add an extension. The slippage was worse, the two set screws just didn't hold the round shank of the bit. Dremel tool and diamond cutting disc. Now the set screws are tight and the slip problem is solved. My advice: make sure your big bits have a slot for set screws, or at least have a hex shank or flat side shank.