The Irwin Weldtec Circular Saw Blades have welded Carbide teeth for a substantially stronger tooth bond and longer life. The ultra compact carbide is 70% tougher than standard carbide for superior sharpness and cut quality. WeldTec on Circular Saw Blades is the welding of teeth to the blade as opposed to the traditional brazing teeth. This is ideal for handheld corded and cordless blades as the weld provides a strong bond in case of unexpected nail strikes or foreign objects embedded in the wood. The blades have innovative heat vents, and the fully hardened plate runs truer for longer and with more accuracy. They have alternate top bevel teeth for cross cutting and ripping in all woods. The IRWIN IRW1897390 Weldtec Cordless Circular Saw Blade has the following specifications:Diameter: 136mm.Bore: 10mm.Reduction Ring: No.Teeth: 18.