These are the best screws I have ever used! The only reason I couldn't give 5 stars was the price. These things went through the woods like a hot knife through butter. The 6" tool had no problem being powered by the 18 volt cordless tool, but you will need a larger drill for the 12" and 14" tools. Had to buy one as my 6 amps weren't enough, but it was worth it as absolutely no pre-drilling was required!