LENOX Tools 1991575 U-Shank Thin Metal Cutting Jig Saw Blade, 3 5/8-Inch X 3/8-Inch 24 TPI, 3-Pack provides users with improved blade durability and long life in thin metal. POWER BLAST TECHNOLOGY® strengthens the blade to reduce breaks and increase durability. Patented T2™ Technology provides fast, efficient cutting in a range of metal cutting applications. Bi-metal technology flexes to resist breaking and extend blade life.