1.Certificate:ISO9001,ISO14001 2.materail:50Mn bottom roller 3.Hardness:HRC50-56\4mm-18mm 4.Tec:Forging ... , Track Link assembly,Track Shoes,Track Bolt and Nuts,Track Bush and Pin,Bucket Pin,Roller Guide,Idler Yoke and so ... :3.Certificate:4.Catalog: Supply PC200-5 Excavator Parts komatsu Bottom roller