Irwin Tools 14028 Marathon® Carbide Tipped Circular Saw Blade, 7-1/4" 18TNew and improved design. Thin Kerf for faster, cleaner cuts. Heat vents reduce heat that causes build up & pitch. Precision honed C3 tungsten carbide tips hold their longer. Round shape means each tooth cuts uniform equal amount of wood. Blade flatness ensures close tolerances. Carbide tipped Marathon circular saw blade New and improved design Thin Kerf for faster, cleaner cuts Heat vents reduce heat that causes build up & pitch Precision honed C3