Petroleum casing is an important equipment for oil drilling. The thread surface of oil casing and coupling should be smooth. Burrs, tearing and other defects sufficient to cause thread interruption to affect strength and tight connection should not be allowed

Steel Casing Pipe, also known as encasement pipe, is most commonly used in underground construction to protect utility lines of various types from getting damaged. Such damage might occur due to the elements of nature or human activity.

Steel casing pipe is used in different types of horizontal underground boring, where the pipe is jacked into an augered hole in segments and then connected together by welding or by threaded and coupled ends, or other proprietary pipe connectors such as the interference-fit Permalok interlocking push-on joint. The steel casing pipe can also be set up and welded into a "ribbon" and then directionally pulled through a previously drilled hole under highways, railroads, lakesand rivers.

Steel casing pipe protects one or many of various types of utilities such as water mains, gas pipes, electrical power cables, fiber optic cables, etc.