... Bearing StructureHigh precision journal bearing. Balls lock the cone.Hardface heard bearing surface. Cone bearing inlaid with friction-reducing alloy. Abrasion ... Optirnized hydraulics structure improves the clearing capability and increases ROP. 5. Product ApplicationIt is suitable for sidetracking, deep well drilling ... 527,537,617 4 1/2114.3517,527,537,6174 5/8117.5517,527,537,6174 3/4120.6517,527, ...