Irwin Tools 24020 Carbide Tipped Marathon® Circular Saw Blade, 6-1/2", 18TThinner kerf provides faster, cleaner, more exacting cuts. C3 carbide tipped teeth are precision honed and impact resistant to hold their edge longer. Unique shoulder design puts more support behind each tooth for smoother, more exact cuts. Specially engineered heat vents eliminate blade warping. Marathon saw blade Universal arbor Thin Kerf for faster, cleaner cuts Heat vents reduce heat that causes build up & pitch Precision honed C3 tungsten carbide