The Lenox Tools 20306BT410S T-Shank Bi-Metal Wood Cutting Jig Saw Blade 4-Inch x 3/8-Inch x 10 TPI - 2 Pack provides users with a clean smooth cut in wood. The 10 TPI allow you to cut quickly, while the sharpness of the carbon steel and the precision ground teeth give you a nice clean finish. The teeth are ground to precision sharpness for straight cuts. The Bi-Metal Construction makes the blade more durable and flexible than a traditional Carbon Steel Blade. These blades are made specifically for jig saws that take T-Shanks.