Irwin Construction Circular Saw Blades have welded carbide teeth for a stronger tooth bond and longer life. The ultra compact carbide is up to 70% tougher than standard carbide for superior sharpness and cut quality.The blades have innovative heat vents and a fully hardened plate that runs truer for longer and with more accuracy. They have an alternate top bevel (ATB) tooth grind for cross-cutting and ripping in all woods.The IRWIN IRW1897397 Construction Circular Saw Blade has the following specifications:Diameter: 216mm.Bore: 30mm.Reduction Ring: No.Teeth: 60.