Engineered for fast cuts, the 3-1/4 in. 36 TPI U-Shank Jig Saw Blade has a milled tooth design. Made from premium high-speed steel, this blade has increased durability and works well on a variety of materials. Optimized for metal cutting, it works well on ferrous and non-ferrous metals, aluminum, and sheet steel. And this blade is only meant for saws that have been designed to use U-shanks.