... boringDescription: 1> Cutting structureIn response to the characteristics that inserts in different areas on the cone have different cutting actions, conical ... body, the bit has good gauge protection and up drill capability3> Bearing StructureHigh precision journal bearing, Ball lock the cone. Hardface heard ... , 527, 537, 6174 5/8117.5517, 527, 537, 6174 3/4120.6517, 527, 537, 6175 7/8149.2517, 527, 537 ...