LENOX Tools 1990703 T-Shank clean wood cutting jig saw blade, 4-inch x 5/16-inch 6 TPI, 5-Pack provides users with improved blade durability and clean, smooth cuts in wood. Power blast technology strengthens the blade to reduce breaks and increase durability. Precision ground teeth with optimized tooth angles provide a clean finish. Bi-metal technology flexes to resist breaking and extend blade life.