Imperial Blades 3MM400 - 3 Inch Circular High Speed Steel Universal Oscillating Saw Blades. This three pack of HSS blades in our line of premium blades is designed for wood, drywall, metal and plastics. Popular uses for this blade: Cutting through harder woods, fiberglass, metals, 20 guage sheet metal, drywall, carbon fiber, etc. 18 TPI (Teeth per inch). Blade dimensions: 3 1/8 inch wide x 1 1/16 inch plunge depth