... and casting Material:40CR or 50Mn Certificate:ISO9001 D7G Bulldozer track roller (9S0316) Liantai Machinery Co., Ltd. Quanzhou produce high ... performance and reliability track roller used for crawler type heavy equipments,such as excavators ... ,Hitachi,Daewoo,Caterpillar,Kato,Hyundai,Volvo and so on.track roller(bottom roller,lower roller)must holds the weight ...