Olylog screws are log home screw fasteners designed to be safer, faster, and easier to use than most traditional log screw fasteners. Rapidly gaining popularity among companies as the ultimate log screw fastener because of its ease of use and its ability to pull and hold logs into position. OlyLog screws have patented head styles countersinks during installation. No pre-drilling required. Gimlet point for fast drilling. Guaranteed by the manufacture not to disintegrate in the new pressure treated lumber. (The new pressure treatment contains a higher amount of copper which affects metal.) Sold by the box. 5/16" hex head - 3/16" shank diameter - 2" of thread with 1/4" major diameter.