The Black & Decker 7-1/4" Piranha Carbide 40T Blade is a true performance blade. This carbide blade provides a longer life and smoother cut versus steel blades.Black & Decker 7-1/4" Piranha Carbide 40T Blade:Performance bladeProvides a longer life and smoother cut versus steel bladesExpansion slots prevent warpingFinishing blade provides a finer cut