Electronic beam weld for stronger, longer lasting teeth. 8% cobalt keeps teeth sharp longer. Bi-metal construction for faster cutting and added durability. Precision-set teeth for faster, smoother cuts. Great for roughing-in work and fast-cutting wood, composition materials, and plastic Use with materials 3/16-inch (5mm) and thicker. IRWIN Tools Reciprocating Saw Blade, Wood- and Nail-Embedded Wood-Cutting, 9-Inch 6 TPI, 5 Pack (372956P5)