As most woodworkers are aware, as of January 1, 2004, the pressure treated lumber industry has voluntarily switched from CCA chemical processes to alternative treating methods such as ACQ. While significant testing has been performed on galvanized screws to ensure their compatibility with the new treatment processes, to date stainless steel is the only corrosion resistant material to have gained widespread acceptance for use with these new materials. ProMax™ Stainless Steel screws are the ideal choice for use with these new materials. Note that because of the inherently lower strength of stainless steel compared to hardened steel, ProMax™ Stainless Steel screws are all #10’s, which provides roughly the same torque strength as the #8 ProMax™ No-Co-Rode screws. Made in Taiwan / China. Unthreaded Length 1-9/16"
ProMax™ Optimized Thread Length™: What It Means and Why You’ll Like It!
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.