... operation in oil and gas wells.StructureThe hydraulic casing section mills are consisted of an upper sub, ... Tungsten Carbide Blades cut through and mill the casing together to increase the milling velocity and increase ... apparatus to help operators judge exactly whether the casing is cut off or not. A drop in ... for 5-1/2" casing, 6-5/8" casing, 7" casing, 9-5/8" casing, etc.More information about this ...