DEWALT DW3724-5 3-Inch 18 TPI Medium Metal Cut Cobalt Steel U-Shank Jig Saw Blade (5-Pack) Metal Made in USA Unique curved tooth design minimizes stress points for longer blade life and faster cuts Cobalt steel (Bi-Metal) maximizes blade life and durability U-shank fits DEWALT and other universal shank jig saws Unique curved tooth design minimizes stress points for longer blade life and faster cuts Cobalt steel (Bi-Metal) maximizes blade life and durability U-shank fits DEWALT and other universal shank jig saws