Number of Teeth - Purpose of Blade
Six - Nail Embedded Woods and Composition Materials
Seven - Flush Cutting
10 - Nail Embedded Woods, Plywood, Insulated Board, Asbestos
14 - Metal Heavier Than 1/8" Thickness
18 - Heavy Gauge Metals, Conduit, Pipe Channels
24 - Metals Lighter Than 18 Gauge Sheet, Trim and Tubing