SUPER FEATURES:the sawtooth was hardened by high frequency quenching, long life, higher tooth hardness, working depth up to 25mm. Work well, accurate. HIGH QUALITY: High mechanical strength such as high strength and toughness. High surface hardness, high fatigue resistance and good wear resistance. Detail feature with bright spot:made of high-frequency quenching, has obtained high mechanical strength such as high strength and toughness.The surface is blackened and the teeth has high hardness, so that they have character of higher fatigue resistance and higher wear resistance. The toothed design makes cutting faster and saves time and effort.