Hello, Guys. Thanks for all the input. Bottom line, the correct screwdriver tip , or insert bit for a magnetic bit holder is critical to ease of installation. Cabinet & door hardware can fool you, I have had to use 4 different screwdriver tips in one installation. (Phillips, Posi, Square #1 and #2 (Robertson). I agree that the square drive & Torx are the best fit between bit or screwdriver, & fastener. The worst, IMHO, are combo drives on any style head, no particular driver, or driver size ever seems to work!!! Regards, Lou