LENOX Tools 1991601 T-Shank power Arc thin metal cutting jig saw blade, 3 5/8-inch X 3/8-inch 24 TPI, 3-pack provides users with up to 2x the life of a straight blade in thin metal and improved blade durability. Curved profile optimizes the angle of attack for fast cutting and longer life Cutting metal. Patented T2 technology provides fast, efficient cutting in a range of metal cutting applications. Power blast technology strengthens the blade to reduce breaks and increase durability. Bi-metal technology flexes to resist breaking and extend blade life.