I have driven a box of 75 so far, attaching 2x4 purlins to 2x8 rafters on a pergola. The include driver bit works well, no cam out so far. You do have to be sure to hold the drill straight or you might get some slippage, but the bit is still going strong. I have a box of 350 left to use and I'm pretty sure the two bits will hold out. If they do not then I have several square drive/Robertson bits that will work also.