We have long period of experience for developing Undercarriage OEM parts. Our entire undercarriage vender is OEM Vender of Komatsu, Hitachi, Sumitomo and other Korean brand such as Daewoo, Hyundai, and Volvo. - Sprocket With high quality cast steel and advanced heat-treatment technology, our Sprockets has superior wear resistance and long lasting durability * A hardened depth of up to 7mm. * Surface hardness: HRC48~55