Deck screws are a good example of Optimized Thread Length. The screws normally used to install 2 x 4’s or 2 x 6’s for decking are 3 inches long and have 1 inch of unthreaded shank. Since 2 x 4 and 2 x 6 deck material is 1-1/2 inches thick, the threads bridge the joint, as shown, resulting in an uneven and unsightly surface, or screws that are over-driven trying to “pull the board down.”
ProMax® screws are different: Thread length is optimized to eliminate crossthreading, and the 1/8” length system allows use of the longest possible screw. In most cases, the smooth shank and self-drilling point allow installation without predrilling! Just select a screw that provides an unthreaded shank length equal to or slightly greater than the material thickness being fastened.

ProMax® Optimized Thread Length Design	Traditional 2/3 Thread Length Design