API: It is the abbreviation of English American Petroleum Institute, Chinese means American Petroleum Institute.

OCTG: It is the abbreviation of English Oil Country Tubular Goods. Chinese means oil special tubing, including product oil casing, drill pipe, drill collar, coupling, short circuit and so on.

Tubing: A tubing used in oil wells for oil recovery, gas production, water injection, and acid fracturing.

Casing: A pipe that has been drilled into the lining wall from the surface of the ground to prevent the wall from collapsing. Drill pipe: A pipe used for drilling a hole.

Line pipe: A pipe used to transport oil and gas.

Coupling: A cylinder used to connect two threaded tubes with internal threads. Coupling: A tube used to make a coupling.

API thread: Pipe thread specified in API 5B standard, including tubing round thread, casing short round thread, casing long round thread, sleeve tapered thread, line pipe thread, etc.

Special buckle: Non-API threaded type with special sealing performance, joint performance and other properties.