Spax PowerLags Screws have a washer head with T-Star Drive and HCR (High Corrosion Resistant) exterior coating. Provides a new level of fastening efficiency and reliability to construction. Engineered specifically for demanding wood-to-wood structural applications, PowerLags feature patented thread serrations that eliminate pre-drilling and dramatically increase installation speed - requiring up to 40% less driving torque to increase installation speed. Fastener length stamp on the head provides convenient identification without measuring and aids on-site inspections. HCR Coating offers superior exterior corrosion resistance when installed in treated lumber and is tested in coastal construction environments. All Spax PowerLags are building code listed and load rated, ICC-ES ESR-1782.