SPAX PowerLag Log and Timber Screws - XTM Pancake Head are the ultimate in heavy-duty log and timber fasteners. With patented thread serrations that eliminate the need to pre-drill, SPAX PowerLag screws will increase your installation speed while preventing cracks in your logs. Code listed, load rated, and corrosion resistant, SPAX PowerLag screws provide peace of mind as you build your log or timber frame construction.