This tool is intended for cutting away a complete section of casing or liner. The cutting blades, lodged in the body, are expanded by mud pressure. They are reinforced with the toughest Tungsten carbide dressing so as to be able to tackle without difficulty the hardest grades of casing. For large diameter casings, it is strongly recommended to stabilize the tool with a freewheeling stabilizer as well as a marine swivel for offshore operations