Ultra-thin kerf delivers more cuts per charge and extends cordless tool battery life. Face-ground, construction-grade carbide teeth for fast, clean cuts and long tool life. Aggressive hook angle for fast cuts. 18 tooth count blades are best for use with medium-thickness metals. IRWIN Tools MARATHON Carbide Cordless Circular Saw Blade, 5 3/8-Inch, 18T Carded (14015)