TB casing back-up tong is a patented product. used to perform casing oper ation by combined with casing power tong and can ensure connection quality and eliminate deformation of main tong under large torque The back-up tong features safety,reliability,labor-sav- ing,and high efficiency.There are two control style: pneumatic and hydraulic.The back-up tong is supplied with a tor que sensor to measure precisely connection torque.The tong is designed and manufactured according to Industrial standard SY/T5074 and API Spec 7K “Specification for Drilling and well servicing Equipment”.