Diablo DS0408CF3 4" Steel Demon Carbide Blades for Thick Metal Cutting, 8 TPI (Pack of 3) DWE4559N more than double the industry more than double the industry standard The steel sleeve along with the Snap Lock™ Adapter (sold separately) creates the first ever 4 cutter full carbide head two step clean hole dust extraction system that removes up to 97% of dust and debris High performance TiCo Hi Density carbide blade delivers an unmatched up to 50X longer cutting compared to standard bi metal blades in extreme metal cutting applications between 3 16” to 9 16” Diablo's Perma SHIELD® non stick coating helps each blade resist heat and prevent gumming and corrosion