Engineered specifically for applications involving sheet metal, including installing ductwork take-offs. Pierce point tip geometry for quick plunging in ductwork. Optimized tooth form designed specifically for cutting ductwork. Tapered profile design allows the blade to make both radius and square cuts. No. 48-00-1630: Length: 3-1/4 In., Teeth Per Inch: 30 TPI, Type: Ductwork, Material: Bi-Metal, Application: Metal and Drywall, Pkg Qty: 5, Package Type: Clamshell