... Certificate:ISO9001,ISO14001 2.materail:50Mn bottom roller 3.Hardness:HRC50-56\4mm-18mm 4. ... all kinds of excavator and bulldozer undercarriage parts,such as Track Roller, Carrier Roller, Sprocket ,Segmnet, Front Idler, Track ... Bush and Pin,Bucket Pin,Roller Guide,Idler Yoke and so on undercarriage parts. Our products have passed ISO14001 ... :4.Catalog: Supply PC200-5 Excavator Parts komatsu Bottom roller