The PWR DRIVE STR is designed to replace lag screws for framing decks or to alleviate the need for standard #10 deck screws leading to potential structural problems.The design of the STR is specific to dimensional lumber used in deck structures and pretty much any other framing needs for that matter, which allows maximum assembly strength. By figuring out all the possible assemblies of a structure, using a mix of 2 x 6 in 152 mm, 2 x 8 in 203 mm, 2 x 10 in 254 mm, 4 x 4 in 101.