TQ Series of Casing Tongs are widely used for making up or breaking out pipes or casings in diameters of4"--13/".The tong heads are designed"open" type and can freely clamp and escape from the casing. TQ casing Tongs are safe,reliable, and easy to handle with high mobility. This series of tongs can be connected to computer controlling units and can serve as ideal well mechanical tool for surface operations in oil fields. National Invention Patent of the tong has been got. The tongs are designed and manufactured according to API Spec 7K "Specification for Drilling and Well Servicing Equipment".