API 5CT 18-5/8 BTC N80 casing coupling

Use: Casing coupling is a drilling tool in the oil field, mainly used for casing connection. The casing coupling mainly solves the problem that the existing coupling is prone to fatigue fracture due to stress concentration. Structure: The casing end is connected with the inner wall of the coupling with conical thread, and the end of the coupling body is connected with the oil pipe with the same thread and the same pitch flat thread. The utility model has the advantages of relieving the stress concentration at the root of the external thread of the single cone thread connecting sleeve, which is not easy to produce fatigue fracture, and the connection effect is good.

The main thread types of casing coupling are: long round thread casing coupling (LC), short round thread casing coupling (SC), buttress thread casing coupling (BC), and the main steel types are :J55, K55, N80, L80, P110 Wait.