In the construction of tunnels, there is a machine that is engaged in the initiation and digging of the machine, called a shield machine, which has the functions of excavating and cutting soil, conveying soil, and assembling tunnel lining. When the segments are assembled, a type of screw plays a role of connection and fastening, and the pipes are assembled to form a cylindrical pipe. The segment is a cylindrical wall; it can effectively control the ground settlement during excavation, reduce the impact on the ground buildings and Underwater excavation does not affect the characteristics of water surface traffic, etc. The segments are combined to form a pipeline. This design is a straight or arc-shaped fastening connector, which is a segment bolt. Segment bolts are divided into hoop and longitudinal. Some designs have the same ring and vertical specifications. In some designs, two specifications, even two strength levels, are used in the ring and longitudinal directions. Generally, the length of the ring segment bolt is longer than the length of the longitudinal segment bolt.