Spax 3571010700750 1/4 x 3" Hex Drive Washer Head Zinc PowerLag Screw (500 Pieces per Pail) The trend setting low profile built-on washer head design offers a contemporary and sleek finished installation. Excellent draw down strength without the need for a separate washer delivers superior clamping ability and a easier installation Check out our Threads!! our patented thread technology allows the screw to be driven faster, is easier to install, and reduces splitting in wood. Let Spax take some of the hassle out of your next project The Blue Zinc coating protects the fastener for interior use so your project will last Heat treated Grade 5 Durability. Subjecting the screw to heat treating gives greater strength and reduces breakage The Hex head drive allows for a strong bit engagement. Better bit engagement means quicker installation with less effort